Crash when saving after rendering

[ManyTracks]

Project with some 60-70 tracks and some 50 Kontakt 5. Running real well in Reaper. Much more solid and fluid and lower RAM and CPU usage than in any other DAW. I love Reaper


Title isn't 100% correct. WHEN it happens it seems to happens when attempting to save. But saving doesn't always induce the crash.


1.
Render a stem of tracks. In this case 12 tracks. Doesn't matter if it renders out to 16, 24 or 32 bit.

2.
After render dialogue window has closed - go to FILE and chose SAVE.

3.
Reaper crashes


Sometimes it crashes WITHOUT going into FILE and SAVE. I suspect that may Reaper is saving a backup in the background and that initiates the crash scenario even without me doing anything.


Sometimes I can do around 100-150 renders and attempt to save. But on render 151 it crashes *when* saving... Or I can make 1 render and it crashes...


The CRASH scenario can end up a little different:

Sometimes Reaper stays in RAM (Open Task Manager) and sits there occupying 6-10 GB depending on the size of the project.

Sometimes it leaves RAM. But when relaunched Reaper isn't communicating with the ASIO UA-25 drivers and it possible to configure it either. Then unbplugging the USB cable for the audio device and re-plugging it can help. But sometimes reboot of the PC is necessary.

Other DAWs work and can export stems etc. Even after Reaper isn't accepting the Edirol UA-25 drivers, other DAWs can be launched and used normally.


Since I'm exporting stems often I'd be really happy if these crashes could be fixed... Thanks in advance


MT