If the action "resize overlay" exists in an event where the conditions repeat true, then even if the event is never evaluated (such as a disabled group,) the Overlay object will resize to 0x0 and cannot be recovered. I found a workaround, by changing the condition to "Every 100th of a second" but this only seems to work right on my dual core computer, and fails horribly on my single core. There are a few other odd bugs with it, such as always stretching the image when resized, even if the option is not enabled.
An example application can be provided, but only owners of the PC game "Doom" would be able to make use of it.
EDIT: Now the workaround is suddenly working on my single core, odd. I also can't seem to reproduce it in a new application, whereas I could before.
EDIT2: This thing totally has a mind of its own, as it stopped working on my single core again.
EDIT3: Now this is getting weird. Yesterday when I made it start resizing after a 5 second delay, it would resize to 0x0, but now it seems to be working fine with an "always" condition after waiting just 1/5th of a second. I don't know what MMF2 was doing yesterday, but some of the weird behavior appears to have stopped. The bug would appear to be that the overlay object hates being resized before the first frame is drawn, however in a new application, resizing it immediately doesn't make it glitch out. Well whatever, I found another bug in MMF2 while trying to sort this mess that is easily reproducable, but that should have its own topic.