If you're still having issues, please check the following:
No name of file to import
Please check that you saved the file - it will let you choose the name.
If you are trying to load a .part file, it means that the file hasn't completely downloaded.
Time zone issues
When saving calendar settings, sometimes your WordPress time zone settings are also changed. Make sure you reset your WordPress TimeZone after changing the calendar settings.
I can’t import all my events, memory error
You will need to increase your PHP memory limit in order to import the ICS feed – please consult with your hosting provider about how to best increase the memory limit on your server.
Could not fetch the URL because robots.txt prevents us from crawling the URL
Change the the WP Privacy Settings. Sometimes it is necessary to wait one or two days because Google caches its information.
See more here: https://wordpress.org/support/topic/robotstxt-8
Some of my event information is missing
Check the Google Calendar privacy settings. Be sure that all events have a public status
How 'refreshing' feeds works
All old events are deleted and replaced with new events. This is done hourly or can be refreshed manually.
My edits/updates to events are overwritten in the calendar after updating
This happens because during the import of events, the existing events are removed and replaced with corresponding events from the imported source.
If you continue to experience issues with your ICS feed
-Make sure you have the newest version of the Calendar and WordPress
-Non-Roman Alphabet characters can sometimes be the culprit. Please make sure your feed does not include these in the feed url.