failed to get configuration 'system.diagnostics'

I'm trying to build a new release of a project I'm working on and I'm getting an error with a standalone build that does not happen in the editor. Specifically:

  System.TypeInitializationException: An exception was thrown by the type initializer for MySql.Data.MySqlClient.MySqlTrace ---> System.Exception: INTERNAL configuration error: failed to get configuration 'system.diagnostics'
   at System.Diagnostics.DiagnosticsConfiguration.get_Settings () [0x00000] in <filename unknown>:0 
   at System.Diagnostics.TraceSource..ctor (System.String name, SourceLevels sourceLevels) [0x00000] in <filename unknown>:0 
   at System.Diagnostics.TraceSource..ctor (System.String name) [0x00000] in <filename unknown>:0 
   at MySql.Data.MySqlClient.MySqlTrace..cctor () [0x00000] in <filename unknown>:0 
 --- End of inner exception stack trace ---
   at MySql.Data.MySqlClient.Driver.Create (MySql.Data.MySqlClient.MySqlConnectionStringBuilder settings) [0x00000] in <filename unknown>:0 
   at MySql.Data.MySqlClient.MySqlConnection.Open () [0x00000] in <filename unknown>:0 

So my question then is can this be fixed temporarily by adding the system.diagnostics configuration to the standalone build?

Considering I didn't have this problem in the previous version of the editor I'm thinking it's the result of a fix to the old MySQL problem that has caused some unintended new problem, but I don't know for sure.

Did you try to set your Api Compatiblity to ".NET 2.0" as opposed to ".NET 2.0 Subset"? I have a similar issue as yours, but alas the Api level doesn't help me in my issue ( though it helped with another issue ). Were you able to get past this issue? Either way, Good Luck!