PSO2's gameguard updated.
It now prevents some applications from working properly. They "stop working" and close while PSO2 is running. This is happening to me and two other friends at the very least.
If your application has a 32 bit version, use that version and hopefully it will help. Common cases include Ventrilo, Media Player Classic, etc.
No official statement from SEGA, affecting both JP and US.
Spoiler!
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