Error 249 when switching characters

For the past few months I keep getting Error 249 occasionally and it is happening more and more often.

Frequently when I switching characters I get the error, click away the messagebox and then am still logged in and continue to switch characters.

Though just now I got the error 5 times in a row without being able to do anything else (error message kept popping up after clicking it away) and I had to log out and back in again.

The entire PSO2 installation folder and the tweaker folder are both exceptions in my firewall and my antivirus software and I did not change any hardware or OS stuff for over half a year before this issue started.

Sega just said to check my antivirus software and I kinda doubt they'll do more with my ip address not being in japan, etc..

Years ago I had this issue but wasn't able to log in and using a bat file to delete ip 4 and ip 6 cache fixed it, so now I set this bat file to run on windows start and also run it manually occasionally but it doesn't seem to change anything.

Any idea what could cause this and what I can do to fix the problem?

Using Windows 7 Home Premium SP1.