Research Tree glitches in X-com TFTD?

There looks to be a full discussion on this page from UFOPaedia. A basic recap is

Glitches in the System

There are two major occasions where research can grind to a halt:

• An alien is required to further research AFTER certain projects are completed

• An object is needed in storage before research is completed

So if X is a trigger to unlock some new research, but it also requires A and B, you need to make sure that you have A and B when you complete X. Otherwise, you may need to complete X again (in the case of interrogations) or be stuck completely in some cases.

The page lists all the places where you can get stuck and how to avoid it.