Insufficient space for detailed definition of the variable key

What causes this issue?

You have used a decision operation that fills the variable key.
However, the variable key is not long enough for this value.

How to fix this error?

You have two options:
You can use only part of the value for the query and shorten it using
the operations VALEN and VAOFF.
If you require the entire value, create a new personnel calculation
rule that contains this and the following operations. Use GCY or PCY to
process the new personnel calculation rule.

Error message extract from SAP system. Copyright SAP SE.