There is this in the plane construction tab, with no model.
Also, for countries that havent researched it, Transports 1's are also available to be built (again, even if they havent been researched)
There is also a slight bug, that happens after a few starts where (research tab) IW fighter, bombs, Light MG, and Engines 1 are unresearched. The equipment after these are, but the starters are not (IE Basic Small airframes would be researched, but IW Small Air frames would not.

The missing research bug would NOT be fixed by a simple UnSubscribe, wait, and re-Subscribe, but only with a complete deletion of the mod file on the computer, then Subscribing