In this released we fixed an issue when uploading attachments via “Add from files”. This fix depends on specific WebApp versions. More information below in ‘Known Issues’.
Further more we’ve improved the version information dialog.
When running WebApp 3.4.5 or newer, the attachments via “Add from files” are broken on save.
This is resolved in WebApp 3.4.9.
Related WebApp ticket: https://jira.kopano.io/browse/KW-2414