I'm running civiCRM 5.28.3 on Joomla 3.9.21 with Mosaico version 2.5.159...
When I try to drag an image into a content block, the dropzone in the content block resolves to a small square, and I cannot drop the image into the content block.
Here's a short video showing the issue: https://www.dropbox.com/s/v0wzy3ttw6crv1m/Mosaico%20images%202020-08-27_15-24-53.MP4?dl=0
Anyone have some insights into how to resolve this (or how to debug it)?
If you are in Joomla and want to edit the mosaico template, than make sure that you are logged in front end and backend of the website.
HTH
Pradeep
We found some sites where drag-and-drop stopped working post-upgrade started again once we did an extra cv flush (sorry if that is drupal speak - you can do via the UI too) - just in case it is as simple as that for you
(Edit) Hmm actually the above was for a separate post-upgrade Mosaico issue, the one relating to drag-drop images stopping was related to some path weirdness which resolved once we upgraded all other plugins (it was a WP site)
