solved by commit:
https://github.com/nextcloud/server/pull/47378/commits/9be51b38e3c1c6df19e550d68c230932062cad18
edit file
in folder nextcloud
/lib/private/Repair/RepairMimeTypes.php
find line
if (version_compare($mimeTypeVersion, '30.0.0.0', '<') && $this->introduceExcalidrawType()) {
edit then
if (version_compare($mimeTypeVersion, '29.0.5.0', '<') && $this->introduceExcalidrawType()) {
finish