Hello,
I have submitted a support ticket but wanted to see if anyone is having a similar experience (or perhaps has a solution).
I installed Acid Pro 9 (32 and 64 bit versions) last week and Acid Pro 10 (64-bit version) last night, and both have the same problem in Windows 10 64-bit OS.
Just after 32 minutes of Multi-Track recording, Acid Pro 64-bit (both 9 and 10) cause a fault in winmmbase.dll, which crashes Acid Pro, and severs all of the recorded tracks. The tracks are about 167MB in size for Mono and 334MB in size for stereo (12 tracks, a mix of mono and stereo, all audio tracks with no plugins or any other software running). I have been able to repair the severed tracks by re-processing them through VLC (essentially to close the severed recording process).
The winmmbase.dll file lives in the Windows\System32 file path (suggesting it is a 32-bit file), which led me to run a test set using Acid Pro 9 32-bit. I was able to successfully record the same tracks in 32-bit without this fault in winmmbase.dll, so it seems that this problem is specifically related to Acid Pro 9 and 10 64-bit versions somehow interacting with this .dll file, which appears to be a 32-bit file.
I have seen where others have reported problems with the winmmbase.dll file crashing Acid Pro at startup, but it has been unclear whether those folks have the same problem in the 32 bit versions.
Google searches have been fruitless at this point as far as finding anyone reporting a similar issue.
So long as Acid Pro 9 or 10 32bit work for me, I suppose it's not a huge deal (and my version of Acid Pro 7 works great as well). I use this software pretty much exclusively to record multiple simultaneous tracks in my studio, and having it crash out at 32 minutes is just unacceptable (as typical sessions last at least an hour between pauses in the recordings).
If/when I get a response from Magix to my support ticket, I will try to update this thread...