SUM / S4 Migration: RFC failed with code 3 key DYN_CALL_METH_CLASS_NOT_FOUND:

Hi!

In step extraction i get the following error:

Severe error(s) occurred in phase PREP_PRE_CHECK/RUN_UCON_REGISTER_FUNCS_PRE!

Last error code set:
RFC system BS2 nr 01 function 'SUBST_CHECK_BATCHJOB'
RFC failed with code 3 key DYN_CALL_METH_CLASS_NOT_FOUND:
The class could not be found at dynamic method call.

In ST22 we see:

An exception has occurred which is explained in more detail below. The

exception is assigned to class 'CX_SY_DYN_CALL_ILLEGAL_CLASS' and was not

caught in procedure

"SUBST_CHECK_BATCHJOB" "(FUNCTION)", nor was it propagated by a RAISING clause

Since the caller of the procedure could not have anticipated this

exception, the current program was terminated.

The reason for the exception is:

At dynamic class method call, the class "CL_UPG_JOB_PROGRESS" was specified,

which could not be found.

The class mentioned in the errorlog doesnt exist on any our systems.
Any idea? Thanks in advance!