Why am I seeing question marks?
Previously, the importer did not reject files that were in an incompatible format. Special characters in these files, like hyphens or apostrophes, were sometimes converted into question marks as a result.
What do I do about it?
To correct this, please ask a Team Admin to:
If the list for that custom field is not already in UTF-8 format: Change the list to UTF-8 format.
import the list again.
What about the custom data I have collected already?
Unfortunately, there's no way to correct the custom data for the existing bookings that show in your Reports. To make sure future bookings have the correct custom data, it's important to resolve this error as soon as you find it.