Error: Cannot Save. (saving file on network due to long filename unsupported).

Error:

Cannot Save. 'Long filename.ext' is an invalid 8.3 file system name.

Cause:

The network directory or drive to which the file is being saved does not support long filenames. For example, if the network is running on Windows 3.11, which only supports the 8.3 naming convention, long filenames used by Windows 95 32-bit applications are not supported.

Solution:

Save the file using an 8.3 file naming convention. The file can be no longer than 8 characters with a 3-character extension.