Unable to import .ics file

I have been trying to import 8 calendars from Thunderbird into eM Client. Seven have been successful but the 8th (most important one) fails. I continually receive the following message: “Cannot import .ics file because folder “X” isn’t a task folder” Pleae advise

Hello,
I guess your 8th .ics file contains tasks. That’s why you keep getting this message. Please drag and drop this file to tasks.

Regards,

Milos KOvalcik.