Cause : Extension I/O configuration failure comes when the I/O extension module types and locations specified by parameters do not match the detected configuration.

1. Check the event log for an auxiliary code.
2. The code indicates which I/O extension module is affected.
3. Check the type and location settings of the modules (parameters 114.01, 114.02, 115.01, 115.02, 116.01 and 116.02).
4. Check that the modules are properly installed.