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- Problems
- ========
-
- This file is part of ArcWeb, and acts as a troubleshooting guide for those
- who have had difficulty installing, configuring and operating ArcWeb. It
- assumes that you have read 'Instruct' and 'ReadMe1st', and if the question
- is about proxies, then 'WotIsProxy' as well.
-
- Recent changes: questions and/or answers for Q24, Q25
-
-
- Question Summary
- ================
-
- Q1. I try to run !ArcWeb I get a message saying:
- "Find ChangeFSI before loading".
-
- Q2. When I try to load !ArcWeb, it says that it requires at least
- version Y.YY of module XXX. What is it and where do I get it?
-
- Q3. When I use the Open URL dialogue box and specify something like
- http://www.demon.net/ in the box, I get an error saying that there is
- no application loaded which can fetch that URL. What's this mean?
-
- Q4. When I try to use the Open URL dialogue box to open a local file using
- local: URLs, I get an error saying that no fetcher is available for that
- URL.
-
- Q5. When I try to use the Open URL dialogue box to open a local file using
- riscos: URLs, I get an error saying that no fetcher is available for that
- URL.
-
- Q6. Sometimes when I load a page, the inlined images are not displayed
-
- Q7. I have heard that UniSys have been threatening to enforce a patent on
- the LZ compression used in the GIF file format, as used by many WWW sites.
- Does this affect ArcWeb?
-
- Q8. When I try to load !ArcWeb, it says 'nager: Sprites22'. What on
- earth does this mean?
-
- Q9. [obsolete & removed]
-
- Q10. How do I change fonts, colours and default options if I don't like
- them?
-
- Q11. How do I set up !ArcWeb for use on a shared network
-
- Q12. I try to run ArcWeb and nothing happens/machine locks up/odd errors
- appear (eg. Permission denied).
-
- Q13. What does icon 'x' do?
-
- Q14. When I follow a link to some URLs, I get a dialogue box saying that
- authentication is required. What does this mean?
-
- Q15. When I follow a link to some URLs, I get a dialogue box saying that a
- non-default port is being used. What does this mean?
-
- Q16. When I try to run !ArcWeb, I get a stack backtrace/Directory Full
- errors
-
- Q17. Why do I get a save dialogue box when trying to read some pages, even
- when the object is HTML?
-
- Q18. Sometimes I get 'Too Long' (or similar) error messages whilst the page
- is being drawn and then none of the graphics are on the page. Why?
-
- Q19. What do I do to cure 'unable to lookup host's address' errors?
-
- Q20. ArcWeb keeps dying with fatal internal error type=5 messages.
- What can I do to stop this?
-
- Q21. When I try to run ArcWeb, I get a message that my Filter Manager is
- too old and that I need version 0.09 or later. Why?
-
- Q21a. Why doesn't ArcWeb attempt to load the more recent Filter Manager that
- I've got in my !System.
-
- Q22. Why does ArcWeb take up so much memory?
-
- Q23. Email and ftp work fine on my machine, but ArcWeb has trouble
- downloading anything at a reasonable speed: why?
-
- Q24. How do I enable the font blending options?
-
- Q25. When I try to run ArcWeb it tells me that "The cache has been locked by
- a browser running on another machine". Should I click Cancel or should I
- override the lock?
-
-
- Questions & Answers
- ===================
-
- Q1. I try to run !ArcWeb or !ArcWebImg and I get a message saying:
- "Find ChangeFSI before loading".
-
- A1. ArcWebImg uses ChangeFSI as its image manipulator. It invokes it on the
- command line to transform GIFs, JPEGs and other formats into RISC OS sprite
- files. If the Filer has not seen ChangeFSI, then ArcWebImg does not know
- where it will be able to find this tool. Open a directory viewer containing
- !ChangeFSI and then try to run ArcWebImg again. If ArcWebImg was auto run
- by ArcWeb, then you will have to quit ArcWeb and load it again, or open the
- !WebHelper application (double-click it - no SHIFT required) and run !ArcwebImg
- directly.
-
-
- Q2. When I try to load !ArcWeb, it says that it requires at least
- version Y.YY of module XXX. What is it and where do I get it?
-
- A2. All the necessary modules are provided in the !System supplied with this
- version of ArcWeb (ie. in the separate toolbox.arc archive). You should merge
- the !System directory with your master copy. RISC OS 3.1 users should run
- !SysMerge to do this. For RISC OS 3.5 and later, double-click on your !Boot
- directory and click on the System icon and drop the new !System directory
- into the new window, although some people have reported that this doesn't
- work properly, but that using !SysMerge does.
-
-
-
- Q3. When I use the Open URL dialogue box and specify something like
- http://www.demon.co.uk/ in the box, I get an error saying that there is
- no application loaded which can fetch that URL. What's this mean?
-
- A3. ArcWeb has rejected the URL as one it cannot handle itself, and it
- has failed to find another application willing to deal with it. If you
- need a specialise application loaded and it isn't already loaded, you
- should load it and retry the URL. Otherwise, look in the Network options
- (from the icon bar Configure submenu) and check that the appropriate
- protocol box at the top of the window is checked. You cannot check WAIS
- because this is not supported by ArcWeb.
-
-
- Q4. When I try to use the Open URL dialogue box to open a local file using
- local: URLs, I get an error saying that no fetcher is available for that
- URL.
-
- A4. This shouldn't happen since local: URLs are handled by Arcweb
- internally. However, this may indicate some failure occurred finding the
- file. This may be because:
-
- i) the filing system you used does not exist
- ii) the URL specified a non-existent file
- iii) you did not specify the URL correctly. Remember that all / and .
- characters after the :: in the filing system name, are transposed.
-
- Remember that these URLs will look odd. Examples of valid URLs:
- local://ADFS::HardDisc4/$/WWW/index.html (ADFS::HardDisc4.$.WWW.index/html)
- local://SCSI::ScsiDisc7/$/Internet/me.gif (SCSI::ScsiDisc7.$.Internet.me/gif)
- local://resources:/$/Apps/!Help (resources:$.Apps.!Help)
-
- Note in particular the strange format for local URLs on filing systems which
- do not use device names (eg. resources:)
-
-
- Q5. When I try to use the Open URL dialogue box to open a local file using
- riscos: URLs, I get an error saying that no fetcher is available for that
- URL.
-
- A5. riscos: URLs were handled by earlier versions of ArcWebLcl. This URL
- naming scheme is now obsolete, superceded by local: URLs, which you must now
- use. NOTE: Running on old version of ArcwebLcl alongside the new ArcWebLcl
- will not work, as support for the riscos: name system in ArcWeb itself has
- been removed. This is because separate routines were needed for resolving
- relative references involving riscos: URLs, and these no longer exist.
-
-
- Q6. Sometimes when I load a page, the inlined images are not displayed
-
- A6. Look at the page's menu under the Options submenu to make sure that you
- haven't disabled the loading of inlined images. There is another problem
- caused whenever ImageFS is loaded and intercepting GIF and JPEG formats. You
- should disable ImageFS whilst using ArcWeb for the moment, although I hope to
- release a version which recognised and takes advantage of ImageFS's
- facilities soon.
-
-
- Q7. I have heard that UniSys have been threatening to enforce a patent on
- the LZ compression used in the GIF file format, as used by many WWW sites.
- Does this affect ArcWeb?
-
- A7. No. ArcWeb does not contain any code for handling GIF format graphics
- files. It merely tests files for filetype &695 (GIF) or for starting GIF87a
- or GIF89a, and pulls out the image pixel size (for imagemaps). [GIF is a
- registered trademark (and service mark) of CompuServe Inc.]
-
-
- Q8. When I try to load !ArcWeb, it says 'nager:Sprites22'. What on
- earth does this mean?
-
- A8. This is a fault in RISC OS 3.50. An error has occurred whilst trying
- to run the !ArcWeb.!Run file but due to the OS fault, the error message
- has been overwritten with the end of the string "WindowManager:Sprites22".
- The error could be any number of things, from a failure to locate a module
- in the RMEnsure statements; failing to set ArcWeb$CacheDir; failure to
- allocate enough memory. You need to check the following common causes:
-
- * Not having FilterManager 0.09 or later (see Q21 for details)
-
- * Failing to load a sufficiently up-to-date version of the DrawFile module.
-
-
-
- Q10. How do I change fonts, colours and default options if I don't like
- them?
-
- A10. There are two levels at which the changes can be made - system wide,
- or user specific. ArcWeb checks the following files for font definitions
- and colour schemes in this order: 1) <WebCache$Dir>.Choices
- 2) <ArcWeb$Dir>.Defaults 3) built-in defaults (you can't change these).
-
- All the configuration windows are linked from the the Options menu on the
- web pages or on the Configuration submenu of the icon bar menu. You can
- alter the settings and then make them permanent by using "Save Options".
-
-
- Q11. How do I set up !ArcWeb for use on a shared network
-
- In order to stop proliferation of ArcWeb into everyone's home directories,
- ArcWeb is willing to cooperate in a network environment. !ArcWeb may be
- installed in a read-only filing system. Users will also need to have seen a
- !WebCache application to which they have exclusive use and to which they have
- read-write access. Only one instance of ArcWeb may use any !WebCache
- directory.
-
- If you are connected to the Internet via a UNIX gateway, then I strongly
- recommend running some form of proxy HTTP server on it.
-
- The system administrator may wish to edit !ArcWeb.!Run to refuse to run if
- Arcweb$CacheDir is not set (as supplied, if it isn't set, it sets it to a
- subdirectory of itself). The system administrator may choose to edit the
- !ArcWeb.Defaults file to change any system wide options.
-
-
-
- Q12. I try to run ArcWeb and nothing happens/machine locks up/odd errors
- appear (eg. Permission denied).
-
- A12. This might be caused by !WebCache not being installed in a read/write
- filing system. Unless you have appropriate archiving software (eg. SparkFS
- or ArcFS 2), you will have to extract the !WebCache application to a
- writable filing system, and then double-click on the WebCache icon to
- install it.
-
- Q13. What does icon 'x' do?
-
- A13. ArcWeb supports interactive help. Load the Acorn !Help application and
- you will be given help about the buttons under the pointer when in an ArcWeb
- window. Note that in the window displaying the page itself, the help is
- purely the URL which would be opened if you were to click SELECT.
-
- Q14. When I follow a link to some URLs, I get a dialogue box saying that
- authentication is required. What does this mean?
-
- A14. To allow information providers to restrict access to certain web
- pages, there is an authentication capability in the HTTP protocol. The
- authentication domain is a combination of the host name and a 'realm' (just
- a keyword indicating which user/password is required). If you do not have
- a valid user name and password, then you will not be able to access the URL.
- If you do, then enter them in the boxes and press RETURN (or click OK). If
- you toggle the authetication window to full size, you will see which server
- is asking for authentication and in which domain. NOTE: Authentication
- checking is performed at the *server* not the client, so you can't get
- around it by hacking at ArcWeb. ArcWeb will cache the user/password
- together with the server and realm and attempt to auto-authenticate you in
- future connections to that server. This cache is destroyed when ArcWeb
- exits (although you can override this behaviour).
-
- Q15. When I follow a link to some URLs, I get a dialogue box saying that a
- non-default port is being used. What does this mean?
-
- Most Internet based protocols such as FTP, HTTP, Finger, SMTP, NNTP etc. are
- defined as existing at a particular 'port' on a server which supports the
- protocol. eg. HTTP is usually at port 80, FTP is at port 21. Sending
- control messages of one protocol to a different server port may cause damage
- at the local machine (your machine!) or at the server, or it may connect you
- to undesirable (and sometimes illegal - although this is very uncommon)
- services. To help you recognise these rogue URLs, you will be asked for
- confirmation when ArcWeb finds that the default port has been overridden
- (except for HTTP, as it is commonly run on port 8001, 8080 as well as 80).
- It's not by any means a foregone conclusion that any non-standard port
- connection is dangerous or illegal, but this way you at least have the option
- of blocking the connection.
-
-
- Q16. When I try to run !ArcWeb, I get a stack backtrace/Directory Full
- errors
-
- A16. You must remove your old !WebCache directory before installing the
- new !WebCache because the directory hierarchy underneath the !WebCache.Data
- directory has changed in order to allow you over a 1000 entries in the cache
- instead of limiting it to 75. If this isn't the problem, then email me the
- stack backtrace. (Tech: you can capture the stack backtrace to a file by
- adding " 2>stacktrace " to the end of the last line of !ArcWeb.!Run. The
- stack backtrace will then appear in a file called stacktrace in the current
- directory.)
-
-
- Q17. Why do I get a save dialogue box when trying to read some pages, even
- when the object is HTML?
-
- A17. If the server did not send, or the fetcher failed to parse, the special
- Content-Type header returned by the server (this won't happen with KA9Q), then
- ArcWeb does not know what to do with the object. From version 0.25, there is
- an option on the Options menu to attempt to 'execute' unknown objects. There
- is also a fix for an incorrect parse of Content-Type headers in A/TCP 0.21
-
-
- Q18. Sometimes I get 'Too Long' (or similar) error messages whilst the page
- is being drawn and then none of the graphics are on the page. Why?
-
- A18. ArcWeb uses external programs to convert GIF and JPEG files into
- RISC OS sprites. To do this, it constructs a command line which invokes
- the translator and tells it the input and output files. When RISC OS runs
- the command string through its routines, it is possible for an overflow to
- occur (ie. the command ends up longer than the maximum permitted command
- length). This is when the OS generates the Too Long error. To fix it, you
- need to move the relevant programs closer to your root directory.
- Specifically, !WebCache and !ChangeFSI are the programs that are
- concerned. Using ..$Path variables does not seem to help, as the OS is
- canonicalising the paths.
-
-
- Q19. What do I do to cure 'unable to lookup host's address' errors?
-
- A19. First of all, check you've spelt the hostname correctly in the URL.
- Check the DNS configuration. Open the DNS tester by choosing it
- from the Show menu on the icon bar menu. If all three of the DNS boxes
- at the top read 'None', then it indicates that the resconf file was not
- found. Check that InetDBase$Path points to a directory containing a
- resconf and hosts files. If it doesn't you need to do:
- *Set InetDBase$path The.full.pathname.to.!Internet.files.
- (including the final .) If the DNS resolvers are known, then click on
- the Lookup Name icon next to the top one. The Answer box should come
- back with the official name of the machine. If it fails, then it means
- that all the DNS servers in your list are not working (or that your
- computer cannot find a way to reach them because you aren't connected
- or something).
-
-
- Q20. ArcWeb keeps dying with fatal internal error type=5 messages.
- What can I do to stop this?
-
- A20. This means that something has gone wrong internally for some
- reason. Although the problem might not be caused by ArcWeb, something which
- it interacts with has caused some condition which was unexpected. The
- best way to deal with this is to follow the instructions on sending
- bug reports by following the link from the default home page.
-
-
- Q21. When I try to run ArcWeb, I get a message that my Filter Manager is
- too old and that I need version 0.09 or later
-
- Q21a. Why doesn't ArcWeb attempt to load the more recent Filter Manager that
- I've got in my !System.
-
- A21/A21a. ArcWeb requires FilterManager 0.09 or later to be installed on
- your machine. It may be the case that you have this module in your System
- directory but have an earlier version in ROM. ArcWeb will NOT kill the
- earlier Filter Manager module if it is active, because some tasks which don't
- behave properly fail to cope with the Filter Manager dying and the whole
- desktop dies task by task. The cure for this is to ensure that FilterMgr is
- loaded BEFORE entering the Wimp on boot up by loading it during your boot
- sequence. For Risc PC owners, this will be in the Misc section of
- !Boot.Choices.Boot.PreDesktop. For other machines, it will depend on your
- setup.
-
-
- Q22. Why does ArcWeb take up so much memory?
-
- A22. Simply because it contains so much code. ArcWeb attempts to cater for
- all kinds of rubbish being downloaded (either maliciously or accidentally).
- Some things which are required are not available as part of the OS, so have
- to be implemented by me instead (eg. multiline text icons in the cookie
- and meta-info dialogue boxes). Some code is included as a work around for
- bugs in the OS (libjpeg).
-
-
- Q23. Email and ftp work fine on my machine, but ArcWeb has trouble
- downloading anything at a reasonable speed: why?
-
- A23. Sometimes the Internet just gets overloaded, however, Web browsing
- puts a heavy load on your computer compared with things like ftp --
- especially if you are using a modem -- and your poor machine just can't keep
- up with all the data being thrown at it. If you are running lots of nice
- desktop enhancements, these can use more processor time than you might
- imagine. Try not using any more software than is necessary when running
- ArcWeb, and use smaller screen modes with fewer pixels and colours to consume
- less bandwidth on older machines. [Thanks to Chris Latham for this]
-
-
- Q24. How do I enable the font blending options?
-
- A24. First of all, you must have RISC OS 3.7 or later. If you don't, then
- this facility (provided by the Font Manager) is not available - sorry. If
- you do, then just enable the option in the Browser configuration window
-
-
- Q25. When I try to run ArcWeb it tells me that "The cache has been locked by
- a browser running on another machine". Should I click Cancel or should I
- override the lock?
-
- A25. This message may appear if your machine crashed whilst ArcWeb was
- running. If this was the case, then you should override the lock. If you
- are using a shared directory for the cache, then it is possible that another
- machine is already using the !WebCache directory. If two running versions of
- ArcWeb attempt to share the same cache, it's asking for trouble (Choices,
- bookmarks and cache contents can become corrupt). If the machine named is
- not running ArcWeb, then you can safely override the lock.
-
-
- --
- Stewart Brodie
- 14th May 1997
-