I have 2 links I usually recommend for a naming convention. I'm surprised to see that the one I posted says nothing about spaces in names, which looks to be the issue. Either that, or it may be the lack of quotes around your control name. Maybe swap or add this link about names because it is specifically mentioned:
https://access-programmers.co.uk/forums/showthread.php?t=225837
Regardless, if you adding the missing quotes I cannot say if the space in Appointment ID will still pose a problem (square brackets are sometimes required to compensate for spaces) because I never use them, so one tends to forget all the idiosyncracies by simply avoiding the issues they present. Also, this site automatically inserts a space after 50 contiguous characters if you don't use code tags, so that is likely the reason for "fsubMedicalT racking"
It might have worked had you been able to write
Code:
Forms("frmMedicalTracking").Controls("fsubMedicalTracking").Form.AppointmentID
but then again, I have found that the syntax I posted for a subform property has given me issues in the past when attempting to use it against subform objects.
For that, I have had more luck with
Code:
[Forms]![Main form name]![subform control name].[Form]![control name on subform]
The square brackets would likely eliminate the issue with spaces in your control names. Sorry if that goofed you up
BTW, I normally don't keep up with cross posted threads since I don't wish to keep going back to the other thread to see what's been suggested there. Can you imagine writing all this only to discover someone suggested this already somewhere else? If you're going to concentrate on this forum for this issue, no problem. If not, I'd like to know.
Thanks.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.