While updating from Nextcloud 18.0.6 to 19.0 there is a integrity problem because of the file "core/img/filetypes/mindmap.svg.
We think the file "mindmap.svg" is copied to core/img/filetypes/mindmap.svg perhaps because of mimetypes, ... This might be ok or not. But with release upgrade there is in this case a problem with integrity check. I think because the normal core package does not include "mindmap.svg".
Thread in german, sorry
https://help.nextcloud.com/t/update-von-18-0-6-auf-19-0-0-probleme-mit-einer-datei-mindmap-svg/85276