Make sure the control names does not match the field names for anything used in your VBA code.
Example:
Control Name: txt1032FollowUpDate
Control Source: 1032FollowUpDate
This helps remove any ambiguity that can confuse Access.
TIP: Posting the code using the forum code tags is much better. The image makes it very difficult to modify your code. When I preview my post before submitting I can;t see the image anymore.
In the after update event it would be the following:
Code:
Me.txt1032FollowUpDate = DateAdd("m",15, Me.txt1032StartDate
This code is refencing the text box controls in a way that is not ambiguous to Access. Access won't have to guess.