Our customer got XXX.err file from file listener, but they did not see any error logs on PegaRULES.log or catalina.out.
Therefore, they run tracer to find out what caused the XXX.err file, and tracer shows following fails.
[Failed to find a 'RULE-OBJ-XXX' with the name 'XXXX' that applies to 'XXXX'. There were 3 rules with this name in the rulebase, but none matched this request. The 1 rules named 'XXXX' defined in the rulebase are:1 related to applies-to class 'XXXX', but were defined on XXXX.]
After they found the fails on tracer, they run the activity directory, and of course the activity failed. However for this time they see error logs on PegaRULES.log same as above.
They fixed a root cause of the issue, but why did they not see the error logs when the activity called from file listener?
Strange. Try repeating the use case with debug enabled on com.pega.pegarules.integration.engine.internal.services.file.FileListener. The PegaRULES log should provide more information about the what happens during error file processing.