Parsing Error ICS file

Hello!

First thank you very much for this wonderful plugin!
I use the free version and are very satisfied with it.

But there is one problem:
In the confirmation email sent to the customers are are links to the different calender-types. As well there is an attached ics-file in the email. The ics-file caused a parsing error and cannot be used.

What can I do to make it usable?
I like this feature very much and it would be a shame not to use it.

Thank you for answer!

Michael