Connection error occurs only on server

My project runs just fine from inside VS on my development box. However when published to the production server it produces this error on startup.
Server Error in '/PAGContacts' Application. -------------------------------------------------------------------------------- Format of the initialization string does not conform to specification starting at index 0. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.ArgumentException: Format of the initialization string does not conform to specification starting at index 0. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [Argum ...