Diplo relation is 1 thing, happiness is an other. Sulphur is still very far. If prussia is AI and you agree the flip, then they spawn without any tech! its a long ago reported problem, didnt followed what happened with it.
I remember a report about no techs on flip, but didn't experience it myself.
But you say it can be reproduced right on the Prussian spawn? If yes, that makes bughunting much easier.
About the pics:
- Diplo penalty from close borders is unintentionally high there, you are right.
- The diplo penalty on the Venetian diplo screen is rare, but it's in the mod for at least a couple years.
- The 3rd picture is the same as the 1st if I'm not mistaken
- Somehow you managed to have pleased relations with France, while being it's worst enemy. Most AI leaders cannot trade techs if you are their worst enemy, no matter how good your relations otherwise. If I have to guess, in this game it was a rare case where France has only met with the Papal States and you, Byzantium (it's safe to assume they haven't met Arabia, and not that uncommon that they don't get a diplo contact with Venice either by that time). They were probably friendly with the Pope, that leaves Byzantium as their worst enemy until they meet another civ. A strange situation when they are pleased with them otherwise.
- On the 5th pic, the attack is possible because Byzantium is earlier in the turn than Bulgaria. I do not consider that a bug. Also, this couldn't affect your spawn stack (units are moved from that area), but a flipped horse archer unit somewhere close to the Byz border. So I don't consider it bad for gameplay either. Just imagine that there was an initial clash between one of your scout units, and the Byzantine defences, foreseeing the long wars to come
- The one with the units on the Sea is very strange. Especially since the stack has some Portuguese unique units, and a settler. Maybe there was an issue with the defensive crusades? Or a wrong flip... Was investigating the related codes for a while now, but so far do not have any ideas... How long were those units there? Were they be able to move?
- The crusading stack in Anatolia wasn't targeted on that city. Probably the target was still Jerusalem, but it changed ownership right before your units supposed to arrive. So your units was placed to a close territory where you had access to, either by war or by open borders. I would need savegame to investigate it further, why were they put exactly there. Btw, what's those buildings on the right side of the picture?
- The last one is a sound entry issue. Are you sure it's from the latest version? I remember fixing some of those a couple commits ago.
EDIT: Oh come on. Just noticed that the bug with the units in the Ocean is from a modified game.
Hanseatic League wouldn't be able to spread to Iberia normally.
Please do not post "bugs" from saves where you manually modified stuff.
In many cases I can't possibly tell if there is a real issue in the mod, or if it was only a strange consequence of some of your edits.
In this case I'm pretty sure though, that something messed up some python processes in the background, that's why those units happened there.