STRMNUMMISMTCH1, Stream nnnn exists on the receiver instance file but is unknown on the source instance
MUPIP Error: Issued by a Source Server on a Supplementary Instance when it detects a non-Supplementary stream number nnnn (which can be any value from 1 through 15) exists on the receiving instance but not on the source instance. This indicates the two instances are not in sync at least with respect to stream nnnn, so replication cannot proceed.
Action: Reinitialize the receiving instance from a backup of the source instance and restart replication between the two instances.