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ORA-12557:

TNS:protocol adapter not loadable
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 is missing or one of its supporting libraries is missing then this error is returned.
Action: For further details, turn on tracing and reexecute the operation. The trace file will include the name of the shared library (or DLL) that could not be loaded.
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1.TNS:protocol adapter not loadable2