ASP.NET Recompilations, Why

We are experiencing a persistent problem with an ASP.NET MVC website.  The website is running a number of machines and all machines exhibit the problem at different times.  What we are seeing is under varying conditions the website begins a recompilation and we cannot determine the cause.  We added some instrumentation on the site by adding code to the application end event.  The message that we see is "Application End - Recompilation limit of 50 reached  HostingEnvironment initiated shutdown HostingEnvironment caused shutdown".  After some searches, we have noted other people with this problem that increasing the recompilation threshold fixes, but as you can see from the error message we have already raised it to 50 and it is still occurring. We can workaround this issue by simply re-publishing the site that we published in the first place or clearing the temporary ASP.NET files in the C:\Windows\Microsoft.NET\Framework64\v4. ...