In this post, you’ll learn more about the Oracle ErrorTNS-12558: TNS:protocol adapter not loaded with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
TNS-12558: TNS:protocol adapter not loaded
Reason for the Error TNS-12558: TNS:protocol adapter not loaded
Cause: On some platforms (such as OS/2) protocol adapters are loaded at run-time. If the shared library (or DLL) for the protocol adapter has not been loaded, then this error is returned.
How to fix the Error TNS-12558: TNS:protocol adapter not loaded ?
You can fix this error in Oracle by following the below steps
Action: For further details, turn on tracing and reexecute the operation. The trace file will have the name of the shared library (or DLL) that has not been loaded.