preuter
2nd March 2012 12:39 UTC

Rare problem with Windows 7
We are distributing a Java application with a packaged JRE. Very occasionally, the installed application can not access some jar files and will not run properly. This only happens to a small fraction of users for a given release, and so far only on Windows 7 machines.

Reinstalling from the same installer.exe does not fix the problem, although a freshly generated installer from identical source code will usually work.

Copying the program directory to another location fixes this problem, and it can also be copied back to the original install location and then run without problems.

This makes me suspect shenanigans with ownership/permissions, although what could cause this is a mystery to me.

Any ideas on the cause, or possible fixes?

MSG
2nd March 2012 14:06 UTC

Given the information you supplied, I don't think permissions can be the cause. I'm more thinking of a file-in-use issue. You should make a debug build of your software and give that to your client. See what error is returned when attempting to open the jar file.

This does not seem to be an installer issue. If the problem is java-related, you should ask in a java-specific forum. Else, you could try the msdn forums.

T.Slappy
5th March 2012 07:24 UTC

Maybe you should create a list of processes which must be terminated before launching your installer.
If they are running ask the user to kill them [using KillProc plugin].

preuter
12th March 2012 00:19 UTC

Thank you for the suggestions. I hadn't thought of file-in-use issues, since the error does show up even after installing/executing after a reboot.

I have added some addititonal diagnostics to the code that will hopefully give us some more data, but so far, the problem hasn't cropped up again (not unusual, it pops up every few weeks at most).