Hello,
I’ve just become the responsible of an another xibo station at another office. well, there are still powerpoint files at their space from 2014. I guess around 300 or 400 files. I could select now each file with the error, select delete, click yes and wait for the next file… or I ask here if it is possible to get some mark boxes to mass delete 100 files at once. Or is that already somewhere and I didn’t find it?
You can use the library tidy. You need to enable it in the settings.
Once enabled, you can automatically delete any media files that aren’t being used by a layout. So to tidy up, delete the old layouts you no longer need, and then run the tidy.
I’ve took a longer look at that tidy now but that won’t help me as of course I have also files uploaded which are not used currently but are in need for further layouts like logos of other firms.
Library Tidy is your only option with a 1.7 series CMS I’m afraid, so it would likely be quicker to add those images to a temporary layout, run the tidy, and then delete that layout.
okay. Will there any mass deletion option with 1.8+? cause then I would wait 
I’m not aware that there is currently. You can certainly post a feature request in the Features category if there isn’t on there already.