Fortigate 800C won't create or edit policies any more

Hi guys, first post here.

Our company firewall won't let me create any policies.

If I press "Create new" at the top, I can create it fine, but if I right click a rule and select "Insert Policy above/below", it creates the disabled policy. But as soon as I edit it, I get to a edit policy screen with no predefined settings, and if I tweak it to the settings I want, as soon as I press done, I'm getting the Entry not found error.

Strange thing is, if I create a rule through the CLI, sometimes I can create a new rule via the GUI afterwards, but after that, the same error comes back.

It seems like there's an issue with the policy numbering.  Is there a proper way to rectify this?