I saw a few other people here and on forum asking about a similar situation where when they tried to log in directly to NGS, the game would just immediately crash to desktop. They then tried to log into BASE PSO2 and would be able to, and used that to transfer to NGS. While they could run around the city just fine, the moment they left they would crash.
This was happening to my fiance ever since this game launched, and we couldn't fix it no matter what (reinstall, verify files, etc). A friend of mine suggested he had a similar issue with PSO2 a while back, and the solution for him was to delete the SEGA folder located in My Documents. Did this for my fiance's computer and everything is working fine!
If you're having this issue I suggest trying this, even if it doesn't help at least you tried. I believe something may be messing up in that folder and causing the game to crash (error log sees it as 1000 on windows 10 so it's application based).
What to do: Make sure PSO2 is closed (chances are it is if you're having this problem...) Locate the SEGA folder, inside your My Documents on your computer. Make sure you back this up if you have pictures / character save information as this is where they save (just copy paste it to a different folder somewhere else). Then straight up delete the ENTIRE sega folder located in My Documents (again, this is not where your game is saved, it's where the game stores chat logs, images, etc). Re run PSO2 NGS and try to log in. Hopefully it works!