Details:

• Minimum client version required: 260
• Current client version: 3
• Installed Version: 2.5.4_3
• Framework: Genten

Error Description: The client shows an "Incompatible Client" message when attempting to use version 2.6.0 PTB81 from the Public Testing Branch. The required protocol version is 260, but the installed client only supports version 3.

This was a mistake made during packaging, an updated release will be made soon that should fix this.