Visual Studio settings files corrupt / MySQL connection issues - mysql

Question

My Visual Studio 2012 Professional is having problems with a three project solution.
I have been struggling all day with a LinqToMySQL.edmx file and getting a MySQL data connection option to appear in Server Explorer.
For this I have tried installing EFTools6.1.0ForVS2012. The mysql connector I have tried is mysql-connector-net-6.7.4. This worked at one point but other problems with MySQL dll versions means I am back to square one (when I got the latest version of the DLL which I got from nuGet 6.8.3, it was still looking for 6.7.4). I have since got 6.7.4 and added the reference to the dll for all project. I've also tried editing machine.config to look for the correct mysql data provider. Still no joy.
But now...
For each solution the app.config or web.config files can't be read when trying to access Properties > Settings.
An error occurred while reading the app.config file. The file might be
corrupted or contain invalid XML
All files seem valid when checked under an XML validator.
When opening a project in VS2012 I get the error:
Microsoft Visual Studio
The ProviderPackage package did not load correctly.
The problem may have been caused by a configuration change
or by the installation of another extension. You can get more
information by examining the file
t:\Users\John\AppData\Roaming\Microsoft\VisualStudio\11.0\A
ctivityLog.xml.
When trying to create a new project I get:
Failed to create a 'ImageSource' from the text
'..\lmages\Medium.png'.
After re-installing Visual Studio the problem persists.
In the activity log the last errors are:
<entry>
<record>235</record>
<time>2014/03/25 10:28:31.202</time>
<type>Warning</type>
<source>Microsoft.VisualStudio.CommonIDE.ExtensibilityHosting.VsShellComponentModelHost</source>
<description>The catalog cache file is not up-to-date and has to be regenerated:</description>
<path>C:\Users\John\AppData\Local\Microsoft\VisualStudio\11.0\ComponentModelCache\Microsoft.VisualStudio.Default.cache</path>
</entry>
<entry>
<record>236</record>
<time>2014/03/25 10:28:31.211</time>
<type>Error</type>
<source>VisualStudio</source>
<description>SetSite failed for package [Visual Studio Component Model Host Package]</description>
<guid>{49D12072-378B-4FFA-A09E-40E0B5D097CC}</guid>
<hr>80131902</hr>
<errorinfo>Configuration system failed to initialize</errorinfo>
</entry>
<entry>
<record>237</record>
<time>2014/03/25 10:28:31.241</time>
<type>Error</type>
<source>VisualStudio</source>
<description>End package load [Visual Studio Component Model Host Package]</description>
<guid>{49D12072-378B-4FFA-A09E-40E0B5D097CC}</guid>
<hr>80131902</hr>
<errorinfo>Configuration system failed to initialize</errorinfo>
</entry>

Answer 1

Looks like most of these errors were caused by malformed XML in the machine.config file in the framework folder. The machine.config file in framework64 was fine which must have caused me confusion. That's what editing with notepad gets you!
Still having problems with the mysql connector but that's a separate issue.