ZDoom

No. What you see is what OpenAL reports.

Hmm. Is there anyway I can get OpenAL to give a more detailed error?

Ok. The problem is, the error doesn't tell me much about what precisely went wrong here.

I am using whichever version of OpenAL comes with GZDoom on the SVN page.

It definitely has nothing to do witg FMod, that code is completely separate.
Also, which OpenAL are you using, the official one or OpenAL Soft?

In the newest versions of ZDoom, using the OpenAL Backend, when a sound environment boundary is crossed, switching into another boundary, the following error is printed -
[spoiler]recieved al error invalid value (0xa003), oalsound.cpp:2198[/spoiler]
This can be seen here: [url]https://vid.me/gwUD[/url] in the Adventures of Square ([url]http://forum.zdoom.org/viewtopic.php?f=19&t=46604[/url]).

I believe this bug may have been introduced in this build [url]http://zdoom.org/Changelog/716fbec/files[/url], because of the addition of FMOD Studio.