It behaves a little different to alt desc in task message outputs. In short you have to click on APPLY when you complete one so it is not altered or lost.
If you add a alt desc and enter text in the text body area, then create another alt desc next to it, what text you enter in the second alt desc will cause the alt desc before it to change its text to what you have just entered. It seems Adrift does not distinguish there are different alt tabs but thinks all of them are the one and the same.
However, if you click on APPLY each time you are finished with entering text for an alt desc then this problem does not occur. Ordinarily you do not have to click apply to make sure your text doesn't disappear.
I am getting even worse errors with this. Often the APPLY button does not become enabled when you edit the text box, the right-click menu changes to the default UltraListBox menu and I can't get alt-descs to work at all.
Location Group: Properties: Adding Alt Desc Glitch
