RAZ-1813: Collection folders could not be moved properly
RAZ-1811: Comments with unicode character could not be saved properly
RAZ-1801: The image thumbnail can not be displayed when it is uploaded in different view like "List view" or "Quick edit view"
RAZ-1818: Deleting a file in another view then thumbnail and on a dedicated file tab will now refresh the list properly
RAZ-1805: Once the rendition is removed the rendtion information is still not refreshed
RAZ-1819: Session timeout should not work properly
RAZ-1820: Collections could not be shown if in another language then the default one
Better flushing of cache
Fixing an issue with threads