Steps to reproduce

1. Have your IP address blocked from account creation on testwiki
2. Try to create an account

Expected results

Appropriately formatted error message is shown

Actual results

Error message with html and wikitext is shown

Screenshots

Engineering notes

1. Verify that this isn't just a testwiki problem and that this would occur on other projects
2. If there's a plaintext alternative, use that instead of trying to apply the formatting and parse the wikitext
3. If there's not a plaintext alternative, circle back and discuss options in eng sync