Just a comment on this issue. After I installed Visual Studio 2015 RTM all my resharper shortcuts were gone. (I had them working just fine with RC) A few of my colleagues were having the exact same issue with Visual Studio 2012.
I tried all the suggestions in here but none worked. The way I found to solve this was to: go to Tools -> Import and Export Settings , select the "Import selected environment settings" and in my case use the Settings I had from my RC installation (you can see that there are files with parts of a date as the filename like: CurrentSettings-2014-09-22). For my colleagues problem I basically sent them my .vssettings that I had that was working on my local VS2012 installation.
This effectively solved the shortcut problem. Further investigation in my case showed that although I applied the Resharper shortcuts they were never bound to the actual shortcut key thats why resetting stuff never worked.