I was looking at active electrodes that I just bought and I noticed some gaps on the protective cover on the top part of a few electrodes. These gaps expose connections of the electrode board. So, I was thinking, wouldnt that be a problem if conductive gel is used?? I mean, it could create short circuits between critical components of the board.
You are correct. In that case it is possible to short-circuit the electrodes.
Either be careful when applying the gel or if you can add silicone in the gaps or heat the already applied one and reshape it.