upgrade wizard "slugs" of TYPO3 9 failes with "something went wrong"

Question

after upgradig an installation from TYPo3 6.2 to 9.5 (via 7 and 8) the last upgrade wizard "Introduce URL parts ("slugs") to all existing pages" crashes. There is no real error message, simply "Something went wrong" in an alert box.

All slug fields in the pages are empty.

Any ideas how to fix it - or to get a better error message?

Thanks!

question from:https://stackoverflow.com/questions/65646929/upgrade-wizard-slugs-of-typo3-9-failes-with-something-went-wrong

Answer 1

Sometimes there is broken Page Data. Did or do You have ext:workspaces activated some time ago? I would Check there for broken Datasets and delete them If not needed. If I remember right, i ran the Update Wizard through cli and got the uid of the First not working Page there.