Visual Studio 2008 hanging when opening designer view

I found myself needing to make some ‘quick’ form changes to an existing windows application. It ended up not being that quick due to Visual Studio hanging every time I opened the designer of a windows form.
After a few unsuccessful searches and trying and failing I came across this blog that did the trick.

Speed up the Visual Studio toolbox

All I needed to do was go to Tools->Options->Windows Forms Designer->General
Set AutoToolboxPopulate to False.

Failure in loading assembly (Event ID:6611)

I was receiving the following error in the event log:

Error: Failure in loading assembly: <assembly name>, Version=<version number>, Culture=….

 

The <version number> in the above error was for the previous version of the affected SharePoint solution.
Although the current version of the solution seemed to be working fine, the above error kept popping up in the event logs. I eventually found the culprit. It was a ‘SafeControl’ entry in the web.config file.

We removed the entry from the web.config file and since then there have been none of these errors logged.