Adding new event on shared Dropbox .ics calendar brings up MODIFICATION_FAILED
I have a .ics calendar on Dropbox that I share with a number of users. I recently added access to this calendar to a new computer and then edited an existing event using this new computer. Since doing this the computer that the event was originally created on can no longer create events nor access the calendar. I have unsubscribed from the calendar and then added again with no fix as well as deleting thunderbird and associated files completely from this computer and reinstalling from scratch and again the same problem persists.
Alla svar (1)
Sounds to me like a permissions issue on dropbox. But then why are you using a single user file type to share calendars. USe a caldav provider to share your online calendars.
THere are many including yahoo and gmail for free, or as you appear to be running a business you could look at something like sogo.https://sogo.nu/about.html either on your own server or on a hosted device. There appear to be lots offering hosted sogo for only a few dollars a month.