Out of nowhere Build fails on XmlException: '.', hexadecimal value 0x00, is an invalid character.

Looks like it is IronSource crapware that is crapping out.

Dunno if you can get rid of that anymore either, but if you can, here’s how:

Extra unwanted packages in new projects (collab, testing, rider and other junk):

About the fastest way I have found to make a project and avoid all this noise is to create the project, then as soon as you see the files appear, FORCE-STOP (hard-kill) Unity (with the Activity Manager or Task Manager), then go hand-edit the Packages/manifest.json file as outlined in the above post, then reopen Unity.

Sometimes the package system gets borked from all this unnecessary churn and requires the package cache to be cleared:

1 Like