How to reproduce
All example files are located in the client ticket

• go to the demo
• Insert event calendar service
• Put the remote calendar (.ics) link on the customer ticket
  (I also insert the file in the customer's ticket)
• Download the calendar from ametys and insert the file into google calendar or outlook
  (if necessary the file is in the client's output)

When we inserts Ametys calendar download into Outlook or Google, events do not appear.
Whereas if we insert the original ics file, the events are displayed