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Windows: 'TNS: Protocol Adapter Not Loadable'Error When Trying To Connect From Another Oracle Home TNS-12557 (Doc ID 556895.1)

Last updated on JANUARY 08, 2020

Applies to:

Oracle Net Services - Version 10.2.0.4 to 12.1.0.2 [Release 10.2 to 12.1]
Microsoft Windows x64 (64-bit)
***Checked for relevance on 3-JUNE-2015***

Symptoms

A Windows machine has two ore more Oracle homes installed. Connections from the usual home are working, but when trying to connect from the other Oracle home (by changing the environment) it fails with error: “TNS-12557: TNS: Protocol Adapter not Loadable”.

A client trace shows these errors:

Cause

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In this Document
Symptoms
Cause
Solution

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