Getting the invalid product key message as well, posting my log here. I'm using the non-steam poe client.
2016-02-28 18:35:11,006 [1] INFO CustomLogger (null) - Exilebuddy Version: 0.1.3853.165
Path: C:\dsfdfdsfdsfsdfds\<ExeName>
OS Name: Microsoft Windows 7 Ultimate
OS Version: 6.1.7601
OS Architecture: 64-Bit
InstalledUICulture: de-DE [German (Germany)]
CurrentUICulture: de-DE [German (Germany)]
CurrentCulture: de-DE [German (Germany)]
2016-02-28 18:35:14,201 [1] INFO CustomLogger (null) - Exilebuddy [0.1.3853.165] is up to date!
2016-02-28 18:35:14,241 [11] INFO CustomLogger (null) - [Pre-Login] Connecting to BestLatency (37.187.151.148)
2016-02-28 18:35:14,500 [11] ERROR CustomLogger (null) - Error while logging into auth:
Invalid product key!
2016-02-28 18:35:14,621 [11] ERROR CustomLogger (null) - There was an error authenticating your key with the server. Please try again or use a different key.
Invalid product key!
2016-02-28 18:35:17,131 [1] INFO CustomLogger (null) - [BotManager] MsBetweenTicks = 15
