Topic on Project:Support desk

I get this error for a specific page (MW 1.31) without following a history link.

The revision #0 of the page named "x" does not exist.

This is usually caused by following an outdated history link to a page that has been deleted. Details can be found in the deletion log.

When I try to edit and save, I get the same error and/or

Someone else has changed this page since you started editing it. The upper text area contains the page text as it currently exists. Your changes are shown in the lower text area. You will have to merge your changes into the existing text. Only the text in the upper text area will be saved when you press "Save changes".

But when saving and then accessing the page I get the same as the first error.

Some sort of DB referential integrity error.

Most common cause is that update.php didn't do the actor migration correctly (see Manual:cleanupUsersWithNoId.php, manual:migrateActors.php)

The migration was many years ago... Is there any solution to this? Nuking the page? Not sure what parameters to include in Manual:CleanupUsersWithNoId.php. I tried php maintenance/cleanupUsersWithNoId.php --prefix '*' --table user

but this did not change anything.

I can see these: https://phabricator.wikimedia.org/T249185 Stackoverflow

i mean, if it was many years ago, but just happening now, the cause is probably different.

You need to figure out what is wrong with db. Basically find the entry in the page table for that page and the corresponding revision entry, and see if anything it references is 0 or missing.

It may have been there all along, but just now I discovered it.

The first screen from a working page, second from dodgy one

https://ibb.co/8sDJ2J5

https://ibb.co/tw6tydF

Revision table

https://ibb.co/RDGbmnc

I can see in a working revision table entry the rev_parent_id has a value, whereas in the non-working one it is 0 but I guess this only means that there are no other revisions for that page.