two different problems.  Sonar sure crashes alot!

I installed PLAY 5  just a few weeks ago and have used it successfully with both Sonar 2016.09 and 2016.10 with no crashes.

I've had nothing but problems with PLAY 5

I don't have any problems with Play 5 except the occasional iLok reinstall prompts, but that happened in stand alone with Play 4 as well and sometimes with Melodyne and Autotune.
 
The MIDI memory thing was a problem for me recently when configuring a Line 6 FBV II foot controller.  I tried the fix suggested elsewhere of deleting all ghost MIDI/Sound devices in Device Manager but that didn't help.  I found I had to open SONAR before I opened any other programs like the FBV controller software.  When I opened SONAR first, I had no further problems. 

Ok, thanks for all your replies.  Mike at East West gave me the scoop on the problem.  I was using the 32 bit play instead of the 64 bit.  If you had the 32 bit on your system you might run into this, as the new play installation.exe ONLY installs the 64 bit, i.e. it doesn't get rid of old play iterations!  so if you run into this you need to delete all east west directories (including the hidden* program data* folder) except for your samples.  Then reinstall with the new 64 bit play 5.
 
As far as the midi thing.  I've already deleted all  the ghost midi ports.  It didn't work.