Many of you are starting to see issues after you installed .net 4.5.1 on your SBS 2011. The symptoms are that RWA suddenly gets flakey.
There’s a couple of ways to fix this. Way one is to plow forward – that is to leave 4.5.1 on the server and throw more RAM at the box and follow the thirdtier blog post on the topic.
Robert Pearman comments on how you need to make the setting.
Way two is to uninstall .net 4.5.1 and then to reinstall .net 4.
In doing so you need to make sure your IIS app pools are set like this KB indicates:http://support.microsoft.com/kb/2619402
You may find your .net is set at v2 versus v4.