I'm using a Yamaha AIC128-D PCIe accelerator interface card for Dante network audio as my desktop pc's audio device with Reaper. Of 128 i/o it's providing I've activated only 24 ins and 30 outs. An RME Babyface is also attached to the pc via USB but I'm not using it with Reaper normally. (side note: Babyface ASIO drivers are multi-client ASIO capable)
Most of the time when I launch Reaper, Reaper shows "audio device deactivated" in the upper right of the window. Even launching Reaper repeatedly doesn't help. Sometimes, what does help, is launching one or more instances of the RME DigiCheck measuring tool which occupies pairs of audio channels of the Babyface. Unfortunately, it doesn't always help as can be seen in this licecap:
If launching DigiCheck doesn't help, I have to switch Reaper to use the Babyface instead of the Yamaha pcie card, then quit Reaper, relaunch it and then set it back to the desired Yamaha settings incl. restoring the i/o channels I need.
I'm happy that I can use the Yamaha card once it has been redefined but it's very annoying to have to wade through the described procedure almost every time I launch Reaper.
Reaper 5.26 x64 Win7 pro x64 (issue persists since I got the card in feb. '16)
EDIT (2017-10-17):
I just found out that Yamaha has released a firmware and driver update for my PCIe card model a few weeks ago. After installing both updates the issue seems to have gone (card properly initializing as it should for one day now)
REAPER is completely vindicated!