ics file and Google calendar - CONFERENCE and X-ALT-DESC

My objective is to enable users to subscribe to upcoming events/import ics files in mailbox.org, ICSx5, Outlook and Google.

Regarding Google calendar: JEM 5.0.1 and also 5.0.2 beta 1 2026-10-19 ics files  can not be imported - message is: Imported 0 out of 0 events. Unable to process your iCal/CSV file. Subscription does not work - there isnt any error message.

Gemini says: 

The main culprit behind the "0 events imported" error was indeed the

Code:

CONFERENCE

tag (and sometimes the complex HTML

Code:

X-ALT-DESC

property) generated by that specific iCal exporter.

I attach the original JEM 5.0.2 beta1 and the Gemini-recommended file to this post. The later can be imported into Google Calendar.