I found this in the flag queue today:
There was no apparent reason why the option was grayed out. Usually everything on Stack Exchange has a handy-dandy tooltip to explain everything you want to know about it, but there was no tooltip when I hovered over the button.
After searching for a while I finally came upon another meta.SE post, Leave Convert to Edit button enabled all the time in the moderator flag list. It explained that you can't convert an answer to an edit from the flag queue (and from the flag queue only; the "mod" menu on the post still works for some reason) if it has comments. There is no official explanation of this that I could find, not even a sentence.
The comment was a "Thank you!" comment anyway. So I deleted the comment (which was more difficult than it should be, and would especially be so if there were more comments), and the "convert to edit" option was still grayed out. I had to refresh the page to get the button working again.
This is all way too confusing, convoluted, and complicated.
My request(s) is (are) that:
Firstly, make the way this is handled more consistent. It doesn't make any sense to prevent taking an action from the flag queue when there isn't even so much as a warning when doing it from the mod menu. I suggest that the following improvements be applied to both the mod menu and the flag queue.
Instead of disabling the button (or keeping it enabled, in the case of from the "mod" menu), implement a confirmation dialog such as the following:
(It's probably best for someone else to decide the exact wording. For example, a sane person would make the last link just "cancel." This is just an example, though.)
Tell the moderator why the action is hidden behind a warning, and explain why said mod should be cautious. I had no idea why the button was disabled, and I don't fully understand why one should be careful when converting an answer that has comments to an edit.
This can be done in the proposed dialog, as shown above.
This would make the whole process much less complex, and greatly improve moderators' understanding of situations such as these.