NC Update fails due to temp file

I’m trying to update Nextcloud from 16.0.1 to 16.0.2.
While doing so, I get an error that says “The following extra files have been found: .rnd”. and it can’t continue with the update. It seems some “.rnd” file created itself somewhere inside the nextcloud folders. But I have no idea, where it comes from and where it actually is located. Some hints? How can I locate it and remove it?

This is the update log:

2019-07-04T19:50:17+0000 TTXtmHP9YC [info] end of checkForUpdate() Update to Nextcloud 16.0.2 available. (channel: "production")<br /><span class="light">Following file will be downloaded automatically:</span> <code class="light"></code><br /><a class="external_link" href="" target="_blank" rel="noreferrer noopener">Open changelog ↗</a>
2019-07-04T20:19:56+0000 JmYZHR9fBO [info] request to updater
2019-07-04T20:19:56+0000 JmYZHR9fBO [info] currentStep()
2019-07-04T20:19:56+0000 JmYZHR9fBO [info] POST request for step "1"
2019-07-04T20:19:57+0000 JmYZHR9fBO [info] startStep("1")
2019-07-04T20:19:57+0000 JmYZHR9fBO [info] checkForExpectedFilesAndFolders()
2019-07-04T20:19:57+0000 JmYZHR9fBO [error] POST request failed with UpdateException
2019-07-04T20:19:57+0000 JmYZHR9fBO [error] Exception: UpdateException
#0 /var/www/html/nextcloud/updater/index.php(1327): Updater->checkForExpectedFilesAndFolders()
#1 {main}
    [0] => .rnd

Your question has been asked and answered multiple times in this forum. Using the the search function could be so easy and fast :wink:

Delete that file and make sure that the Nextcloud root directory is not the home directory of the web servers user.