I created a test project where I added several items to a listbox control and created a custom action to remove the selected item in the listbox. It only removes the selected item if there are less than 10 items in the listbox, however when there are more than 10 items I get the error "ERROR_NO_VALUE" and the remove button does not do anything. Is there something I'm missing? I've attached a test project showcasing this.
I have tested this and I was indeed able to reproduce this issue. Unfortunately, we were not able to find the root cause of this. I have forwarded this to the dev team and hopefully this will be fixed in a future version of Advanced Installer. Thank you for bringing this to our attention.
After further investigating this, I could notice that if you do the "Populate" action from within a VBS, it works as intended (which is pretty strange to be honest). So, as a workaround, could you please try to do the list box population from a VBS (i.e. replace your PowerShell with a VBS and execute the PopulateListBox action from within the VBS using the "Session.DoAction" method)?