An error occurred while trying to access the server

Product:
Cognos Controller 85

Symptom:
Error when you try to start Cognos controller client, after the selection of the database.
“An error occurred while trying to access the server.”

Message in Windows event log:

Event Type: Warning
Event Source: Cognos Controller
Event Category: None
Event ID: 0
Date: 2010-05-11
Time: 15:03:15
User: N/A
Computer: SERVER
Description:
Error occured at 2010-05-11 15:03:15 in IBM Cognos 8 Controller, Error No=5, Source=FrangoDirect.ConnectionDirect.GetUserInfo#ControllerProxyClient, Description=System.Web.Services.Protocols.SoapException: Server was unable to process request. —> System.ArgumentException: Format of the initialization string does not conform to specification starting at index 0.
at System.Data.Common.DbConnectionOptions.GetKeyValuePair(String connectionString, Int32 currentPosition, StringBuilder buffer, Boolean useOdbcRules, String& keyname, String& keyvalue)
at System.Data.Common.DbConnectionOptions.ParseInternal(Hashtable parsetable, String connectionString, Boolean buildChain, Hashtable synonyms, Boolean firstKey)
at System.Data.Common.DbConnectionOptions..ctor(String connectionString, Hashtable synonyms, Boolean useOdbcRules)
at System.Data.SqlClient.SqlConnectionString..ctor(String connectionString)
at System.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous)
at System.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(String connectionString, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions)
at System.Data.SqlClient.SqlConnection.ConnectionString_Set(String value)
at System.Data.SqlClient.SqlConnection.set_ConnectionString(String value)
at Cognos.Controller.Proxy.DAL.Xcamusers..ctor(String sGuid, String sUser)
at Cognos.Controller.Proxy.ControllerReportNetService.RepNet.GetUserInfo(String sGuid, String sUser, String passportId)
at Cognos.Controller.Proxy.CCRWS.GetUserInfo(String sGuid, String sUser, String passportId)
— End of inner exception stack trace —, HelpFile= HelpContext=0

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Cause:
The SQL login that is used to access the Cognos Controller database have a = sign in the password.

Solution:
Change the password used by the SQL login Cognos to the controller database to only contain letters and numbers (e.g. A-Z, 1-9)
Then change in Cognos Controller Configuration for the database connection to the new password for access to the Controller database.
Save the change and restart the Controller Application server to allow the controller services to understand the change in connection to the database.