The fits header DATE-OBS currently causes trouble with comet alignment. If this header contains a trailing timezone info character, the comet alignment module crashes with "unknown exception" when adding files.
Meanwhile I found out that PixInsight follows the FITS specification, but the error message at least is not very helpful.
Although the problem's origin is not PixInsight itself but wrong header data - for example created from the current INDI implementation, it would be better if (a) the module gives a good problem hint and (b) ideally simply ignores the time zone character.
Since 21P/Giacobini-Zinner is observable, many people (like myself) do the first comet alignment and might observe the same problem.
