I don't know if anyone have incounter this problem, I am just having this in the paste week. My add-on had no problem with User form, but I created on from screen printer as I have done before, put in, set a button unique id 2 and now, when I close the form, or hit cancel button. The addon stopped working. System form additioanl control goes away.
I tried to try and catch everywhere and nothing returning any exception. ... Very weired. Anyone can help I apprecate it a lot. Thanks