This is pretty hard to diagnose with just a screenshot. Most likely whats happening is there are some dimensional differences between the current spec and the spec changing to. The pipeline may not be able to accomodate these changes due to dimensional constraints or similar.

Something I ran into the other day with convertfromprjdata was 2 x valves that had been copied across from another line by one of the users. Had to run reassociatemodel in order the update to work correctly.