SQL Server connection errors when moving .net app to new server

I'm fairly sure the solution is to remove the instance name from the connection string...

"Server=mysqlserver,3050;Database=Idea;Trusted_Connection=True;"

Refer to these questions question1 & question2

"It's not necessary to specify an instance name when specifying the port."

Problem was due to hidden characters in the connection string. See my Edit 4. Other problems leftover were unrelated.