Help me i can't play the game since the maintenance, i meet the lauching error 5 again & again & again, uninstalled & downloaded the game but nothing work!

Try these options (Also, check if there are other posts about this issue before making your own)

PSO2 Tweaker to fix file permissions

Manually fix permissions

1. Open Game / launcher (don't close)
2. Right click pso2_bin folder. Click Properties > Security > Advanced. Check "Replace all authorization entries.
3. Close Game / launcher
4. Repeat step 2
5. Open Game