Any file operation error at Special:MovePage give "permission errors" which are wrongly formatted.
Example:
"You do not have permission to move this page, for the following reason:
<swift-local-backend-pmtpa> "
Likewise, at Special:Upload I get things like:
"Internal error
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Error storing file in 'C:\wamp\tmp\phpE1C0.tmp': backend-fail-connect; swift-local-backend-pmtpa"
Version: 1.20.x
Severity: normal