Error starting SQL Optimizer: "Quest.Tuning.Oracle.Main has encountered a problem and needs to cl (4306961)

When starting  SQL Optimizer form Start menu  or from Toad, the following error occurs:

"Quest.Tuning.Oracle.Main has encountered a problem and needs to close. We are sorry for the inconvenience."

WORKAROUND 1:
Check to  ensure Microsoft .NET 2.0 SP1 is installed. (If installed then ensure that the file 'machine.config' in 'C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG' has not been corrupted)

WORKAROUND 2:
1. Extract the MSI for SQL Optimizer by running '"path\installer_name"/extract' at cmd prompt.
2. Extract the SQL Optimizer MSI.
3. Install QuestSQLOptimizer_Oracle_Common.msi.

STATUS

Enhancement request ST65525 has been submitted to Development to make the error message more verbose to help pinpoint the cause of the closure.