Ok I'm making this post because several people have reported different issues/problems in-game.
For past couple days after maintenance I've suffered terrible in-game lag regarding cast animation etc. Mob health and my own character health not updating till end of combat, which makes it pretty tricky to guess whether you are going to survive a particularly risky fight.
Also this evening I've had something happen that I've never seen before.
In the craft window (on my dragon) when clicking on 'tool' I get several identical lines of spam in general chat-box:
<<Format Error>> not found for deconstruction
A friend of mine has also experienced falling through the world and a few others reporting issues using portals.
I just thought it would be helpful if I start a thread for people to report any issues on to be helpful in resolving the problems.
Currently using Client 390.38 as well. And have ran full scans several times.