I have not heard of such a limitation but you are unclear on some of the details.

if you export an hour long file, does it cut off at 36 minutes, too?

Does the export show done or does it hang? 

Are you saving to the boot drive or external media?

Could your computer be going to sleep during the export?

Yes, the hour long files also cut off at 36 minutes.

I think I may have discovered part of the problem.

I need to back up to how the musx files were created to begin with.

They all began as MusicXml3.1 output from a program I wrote to generate random music.

I imported the Xml into Finale.  Then, I exported the audio file to my hard-drive.

The exports do not hang.  They take maybe about a minute to finish.

No error messages are displayed.

Now, just for fun, I tried to create a 40-minute long score by starting with a Finale template, and copying music from

various scores that I previously created in Finale.  THAT score, when exported to a .wav file, created a 40-minute audio file correctly.

So, the problem seems to be in how I create my MusicXML file.

I tried copying the 4 voices of what I generated to a violin quartet that created with Setup Wizard.

THAT file exports correctly and gives me an audio file that is the right length.

So - any XML wizards out there have any ideas what I might be doing wrong in my program?

Thanks!

The other thing to watch out for is that the latest version of Finale only appears active while it creates the structure for the audio file; then only the (small and possibly overlooked) timer ticks off while the file exports. If one closes the file or proceeds with other work, it is possible to cut off the export before it has finished. Usually, however, this results in a useless file rather than just a short one.

One version (was it 25?) showed the cursor moving rapidly through the music as the audio exported, but for whatever reason that has been abandoned in the latest version.

As the problem appears to be related to your MusicXML scripts, you want to use the Submit a request link at the top of the page and ask support to take a look. Although Mr. Good sometimes shows up on these boards, it’s never a given that he will do so. A support request should get it to his team.