Meeting invitations don't support attachments
When a meeting is scheduled and includes an attachment the meeting invitation that is sent out includes a field that points to the attachment. In Evolution (3.38.3 on Debian Bullseye), when I open the meeting invitation I'm told:
Unable to send item to calendar “Cat - Andrew”. Cannot receive calendar objects: Error opening file /path/to/attachment/on/senders/computer: No such file or directory
Which, while it is understandable, is worrying, and misleading to users. I also am not sure if the meeting was actually created or updated (this example was an update to an existing invite). Especially as people who schedule meetings keep thinking that they can add attachments that other people can read. I expect this might work if a network share is used.
An example from the meeting invite:
ATTACH;FILENAME=3DName of File.extension:
file: ///path/to/attachment/on/senders/computer
Perhaps when a meeting invite is sent, the dialog window could ask if a reference to the attachments (if present) should be sent, or include wording that the file itself is not sent as an attachment. If it is possible to actually send the attachments, that would be even better.