Photoshop elements 2018: motion reduction prevents export (error code)

Hallo

I am desperate: I finished a long video, and used the motion reduction tool once during creation. Now I want to export the video, and each time the export window shows the error code (maybe not 100% correct words): " Motion reduction still running or not working correctly- Please wait until finished or fix the problem"

I tried:

- deleting the motion reduction from the film by using the bin symbol

- undoing it with the respective symbol

- redoing the motion reduction (now 3 times in different versions)

- of course saving the file under a new name

- opening the film on a different device with adobe premiere 2018

Please help - I have no chance to export the file into a version I can use, now.

Thank you!

eva