You may have a problem on your Joomla install, or iCagenda... Or access permissions to folder or files...
JFILE is the joomla core function to download a file.
Try maybe first to re-install iCagenda.
Then, try too to empty cache of site and admin, and expired files
Latest version : iCagenda 3.9.8
We recommend every user to keep iCagenda updated. Don't forget to have your Joomla!™ up-to-date! Do you like iCagenda? I would appreciate if you could take 5 minutes to post a review on JED (Joomla Extensions Directory)
.