I just updated Visual Studio 2015 with Update 2.
Now, after few hours of working fine, I received: "Low memory detected. Full solution analysis disabled for this solution." that appears on the top of my editor dock panel of VS2015.
I saw that a bug had been reported at Microsoft Connect.
Notes:
If anybody has a workaround or a hint on what to do to solve this, please let me know.
Update: I have pretty much the same feelings as Anders Forsgren (first comment). That's sounds to me a good summary of the situation.
Update 2 (2016-04-20) I recently (3 days ago) made a big clean up of my Framework.Net installed packages (from "Programs and features") where I removed about 20-30 packages. Some were in Russian. I also re-installed Visual Studio and ReSharper. All of that seems to have add some stability to my environment (less or no more freezes -> time will tell). Also, there is a new (2016-04-19) .NET Framework Repair Tool Version that came out recently. Perhaps it could help to fix some of our problems, if any related?
Update 3 After some tests and read some peoples text. It seems that it is not related to .Net framework itself or Resharper. It seems to be related to VS2015 itself, probably Roslyn. I didn't success to remove Roslyn/CodeAnalysis from VS2015, it appears to be an essential part. It sounds like we will have to wait for a Microsoft fix to have a stable environment.
Update 4 (2016-04-26) See John Atwood answer. Lots of information. I just started to test its answer. Update 3 should solve this issue (when available ???).
Update 5 (2016-04-26 + 6 hours) After 1 restart done by VS itself, one incredible slowness and also one message "Low memory...", I could confirm that disabling Full Solution analysis does not fix the problem, at least on my machine. I currently don't know any fix/workaround that works on my machine.
Update 6 (2016-06-15) Mladen Mihajlovic woke me up. I just realized that I forgot to tell about the availability of VS2015 Update 3 RC (please note that I think it is the second release: Update 3 RC2). It is available since june 7 at MSDN, RC1 = 14.0.25401.00 while RC2 = 14.0.25402.00. It sounds to be a lot more stable (I highly recommend it).