PSA - Don't try to do RDM instanced quest.

[Bridgeburner]

any solo-instanced combat specific to Version 4

Not so much; My fresh lv47 is stuck behind "Fool Me Twice", a lv 46 solo instance in Mor Dhona. Same symptoms otherwise;

1) black screen when I try to zone into the instance
2) Dropped from the game with a 90006
3) Log back in to a "world is full queue"
4) Repeated drops with the 90002 error, as noted

My timeout's shorter than 30 minutes - more like 10 - but perhaps that depends on the instance in question.

You might have gotten lucky with your 3.x solo content. I was able to do some solo instanced content in 2.x earlier today, too, but as prime time started to kick in that's been a no-go. The random server lag and disconnects are already rough, but at least they don't keep me out as long as the instance problem.