Forgot page should be there by default.
I'm thinking maybe you've changed your URL structure for some option that is not a [OK] link option in the Admin Panel. So that error could be generating because of that.
Admin > General > URL Structure
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.