First of all, why do you have so many empty "Row" entries? I wouldn't be surprised if that was causing mayhem.
Second of all, I don't think it's possible to disable ideologies through XML alone, you also need to consider it will utterly break the UI element (Policy Screen), and might even become unhinged when the game tries to trigger the Ideology Selection because no Ideologies are present.
You also shoved the PolicyBranchTypes within the PolicyBranch_Disables, which means the game is tryhing to search for PolicyBranchTypes inside the Disable one, they should be on seperate tables instead
So move the PollicyBranchType block underneath the closing (</) of PolicyBranch_Disables