If you get the below errors and are not using the KDE desktop environment, it could be that you installed some KDE program like Okular and then removed it, as a result it caused the mime types to give following errors:
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Unknown media type in type 'uri/mms'
Unknown media type in type 'uri/mmst'
Unknown media type in type 'uri/mmsu'
Unknown media type in type 'uri/pnm'
Unknown media type in type 'uri/rtspt'
Unknown media type in type 'uri/rtspu'
To overcome the errors, open a terminal window and enter the following commands:
$ cd /usr/share/mime/packages <enter>
$ ls -al kde.xml <enter>
If it exists, then:
$ sudo rm kde.xml <enter>
$ sudo update-mime-database /usr/share/mime <enter>
That should resolve the error.
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