Not so strange, but it's a nice sight nonetheless
I'm the Byzzies, and France DoWd Austria, my ally. Austria were getting their ass kicked in until I noticed that France was on 0 stab... so I went and spammed a few spies to bring them down to -3. After that, I let attrition kick into the French doomstacks, and finished them off myself. Result was a France with 18 WE, -3 Stab and no army. I then simply white peaced out, as I don't really care for France's land and was busy fighting Milan.
Oh, and by the way. That light green colour that's slightly different to Portugal is Parma. France had taken Parma from Milan way back, and Nationalist rebels established Parma.. who then proceeded to start kicking some French ass. Even Trier DoWd France! (Though the idiots decided to white peace out...) Also, religious rebels have run amock. Half of the country is reformed, the other half protestant... and France is in a state where it can't convert!
Though, what was strange is what happened several years before this war.
Now, Riga previously held Livland (don't ask me how Riga beat the TE... probably gained a core via event and got a rebel defection), and for some weird reason, France got involved with a war with them and took it. Strangely, despite France currently owning it during their current state and having a 32% RR there, there's no rebels at all.