ORA-12571 error example.

The oracle11g system suddenly encountered such an error. Server Error in '/PSM/CSR' application.

Failed to execute reader. (ORA-12571: TNS :???????)

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. servicemodel. Comment '1 [[paymedia. applicationservices. sharedcontracts. ibsfault, paymedia. applicationservices. sharedcontracts, version = enabled, culture = neutral, publickeytoken = NULL]: failed to execute
Reader. (ORA-12571: TNS :???????)

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.

Modified the sqlnet. ora file,

Sqlnet. authentication_services = (CNT) to (none)

The result error disappears.

Then, change none back to the CNT, and the problem does not occur again.