Error mesage after upgrade / Fehler nach Upgrade

🚧 Installation
1

Nach dem upgrade von ownloud zu nextcloud hatte ich diese Fehlermeldung. Unter File Sharing not working after migration from OwnCloud (9.4) to Nextcloud (10.0) habe ich gelesen, dass dieser Fehler ab Version 11. nicht mehr vorkommt. Aber nache einem Update auf 11 und auf 12 kommt der selbe Fehler immernoch.

After an upgrade from owncloud to nextcloude i got this error message. In File Sharing not working after migration from OwnCloud (9.4) to Nextcloud (10.0) I read, with update 11. the error is solved. But isn´t

{“reqId”:“XVqEOlKlViEAAHtRbHUAAAAV”,“level”:3,“time”:“2019-08-19T11:12:58+00:00”,“remoteAddr”:“XXX.XXX.XXX.XXX”,“user”:“UserXXX”,“app”:“index”,“method”:“GET”,“url”:"/",“message”:“Exception: {“Exception”:“InvalidArgumentException”,“Message”:”",“Code”:0,“Trace”:"#0 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Share20\/DefaultShareProvider.php(849): OC\\Share20\\Share->setSharedBy(NULL)\n#1 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Share20\/DefaultShareProvider.php(768): OC\\Share20\\DefaultShareProvider->createShare(Array)\n#2 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Share20\/Manager.php(1121): OC\\Share20\\DefaultShareProvider->getSharedWith(‘UserXXX’, 1, NULL, -1, 0)\n#3 \/homepages\/3\/d123456789\/htdocs\/owncloud\/apps\/files_sharing\/lib\/MountProvider.php(75): OC\\Share20\\Manager->getSharedWith(‘UserXXX’, 1, NULL, -1)\n#4 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Files\/Config\/MountProviderCollection.php(108): OCA\\Files_Sharing\\MountProvider->getMountsForUser(Object(OC\\User\\User), Object(OC\\Files\\Storage\\StorageFactory))\n#5 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Files\/Filesystem.php(445): OC\\Files\\Config\\MountProviderCollection->addMountForUser(Object(OC\\User\\User), Object(OC\\Files\\Mount\\Manager))\n#6 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Files\/Filesystem.php(374): OC\\Files\\Filesystem::initMountPoints(‘UserXXX’)\n#7 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/legacy\/util.php(280): OC\\Files\\Filesystem::init(‘UserXXX’, ‘\/UserXXX\/f…’)\n#8 \/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/base.php(1004): OC_Util::setupFS()\n#9 \/homepages\/3\/d123456789\/htdocs\/owncloud\/index.php(42): OC::handleRequest()\n#10 {main}",“File”:"\/homepages\/3\/d123456789\/htdocs\/owncloud\/lib\/private\/Share20\/Share.php",“Line”:292}",“userAgent”:“Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0”,“version”:“12.0.13.2”}

Kann mir jemand weiterhelfen?
Can anybody help me?