I had a similar problem today and sadly my conclusion is it can be anything.
In my case the culprit was the archiveArtifacts that failed because it couldn't find anything to archive.
It silently marked the build as failed without any output in the console or the build pipeline steps page.
Since the build was going on a bit after that it took me some time to find it.
My advice is to comment out as much as you can, running a build without publishers and make sure it succeeds.
Then add publishers one at a time until you find the cause, assuming one of them is the culprit.