This is a scripting error that should (of course) not be occurring. The "access is denied" error is ultimately coming from Windows and would be outside of the control of XMetaL Author Enterprise.
The file that is being manipulated in this case is probably the one located here:
That file stores settings you set up in the Configure Output dialog.
Here are some possibilities:
1. Windows security settings on your machine are stopping files in the per-user area of your system from being read or written to.
2. The file is temporarily locked due to some kind of Windows glitch. Rebooting or logging out of Windows should help.
3. Some 3rd party software is stopping files in the per-user area of your system from being read or written to. This might include anti-virus software, or it might be something malicious or something else interfering by mistake.
4. The software might be broken (one or more files are missing or corrupted) in which case you should try removing the file listed above so that it can be recreated. If that doesn't correct the issue then you can try to reinstall after removing the file listed above.
5. A hardware glitch (possibly the hard drive) is stopping files in the per-user area of your system from being read or written to properly. If this is temporary then rebooting might correct the problem (memory issues). Otherwise, using Disk Check (https://support.microsoft.com/en-us/kb/2641432
) or another tool to check the hard drive for errors might be necessary. Once they are fixed you would likely have to manually remove the file listed above so that it can be recreated. If other files in the installation are affected you might need to reinstall. This is similar to #4 except that we're assuming there is a consistent issue with the hardware that needs to be identified and corrected (hence the use of the Disk Check tool).