Thanks!
I know the reason of the problem now.
This is this plugin :
PHP Image Editor - Edit your images directly in Joomla!
So, i have disable it and it works!
If you doesn't need it, let it unpublished, or uninstall it, as it seems not stable, as conflicting with Joomla button...
Description in iCagenda category and event is displaying joomla button image, and that may be why there is an error !
About some tests on your admin, can you please check the plugin "Inschakelen" and/or "Uitschakelen", only system plugins (use filter) as i may have publish one or two that were unpublished before...
This is the only place where i have done something, only by publishing, and unpublishing plugins, to find the one responsible of the conflict !
Hope you will enjoy iCagenda now !
Regards,
Lyr!C
note: if you need this plugin, maybe contact the developper to know where is the problem...
info: you have some buggy plugin, maybe not correctly install, or uninstall. for example, this one can't be open, error : PLG_SYSTEM_ADMINBARDOCKER