The event types ProcessInstanceChange and ProcessStepInstanceChange used in the wm_process template are used in PPM 25.15 cm their version 2.0. To migrate a client that is based on this template, you need to import all data still based on version 1.0 event types into the currently used PPM version 9.x.
Procedure
Start CTK 9.x.
Extract all data of the channel Event::WebM::Process::V1_0::ProcessStepInstanceChange of the PROCESS_STEP Universal Messaging data source.
Extract all data of the channel Event::WebM::Process::V1_0::ProcessInstanceChange of the PROCESS Universal Messaging data source.
Make sure that no new data will be written to these two Universal Messaging channels after the extraction.
Then import all data extracted from the two data sources into PPM 9.x.