I'm still playing an old 1. 6. 3 campaign where some bugs crept up and I unfortunately haven't had the chance to replicated them yet in 1. 7. x. I've been trying to keep up with the bug reports though and didn't see these mentioned anywhere yet.
Bug 1:
If you have a station with 0 fuel capacity (like a terraformer that doesn't need fuel), then tug it somewhere, then put a tanker in that fleet with 'refuel own fleet' orders on, you get a flood of '854' divide by 0 errors. Detaching the fleet seems to have resolved the issue.
Bug 2:
This one will be hard to replicate. Over the course of the campaign, a couple of survey vessels were lost to . . poor maintenance practices. Many years later, I started a conflict with an NPR. In the first engagement, I destroyed two of their ships. In the event log, I got messages about my scout ships that had been destroyed a long time ago!! ('transdimensional kills. png') Note that I also lost a third survey ship before this, but that one I did 'abandon ship' to try and save the crew, and that ship did not show up in the even log. I don't think any other ships have been destroyed yet in the game, and since that time, I haven't destroyed any other ships, only missiles, so I can't comment on whether it's just a one off thing.
I have the DB for this but it's 1. 6. 3 so might not be useful.
Bug 3:
I am in combat intercepting incoming missiles. Part of my armament is particle beams, which open fire at 200k or so. However, the fire control for these particle beams has an enemy ship targeted (in this case, the 'Algaciras 001'), even though that ship is millions of km away. (I was a bit eager with my targetting) Most of the hits miss, and it seems from the event log that the targeting is being correctly calculated using the missile salvos. But a beams do hit, however note the damage report says that it is the 'Algaciras' that took the damage! This happened again in another salvo, and there the message differentiated between armour hits and penetrating hits, which suggests that the damage is actually being applied to/calculated for the ship, not the missile.