Issue Summary

When accessing an non-existent with a pattern like ' https://fqdn/display/xxx', If profile language is in Japanese (or other multibyte language), a  garbled character page of 'Page Not Found' will be returned.

Also, 'Page Not Found' page won't show garbled character in below URL pattens.

• https://fqdn/404
• https://fqdn/calendar/404
• https://fqdn/plugins/404
• https://fqdn/spaces/404

By my test this problem does not happen in confluence 7.x.x, it seems a bug introduced since 8.0.0.

This is reproducible on Data Center: (yes) 

Steps to Reproduce

1. Set user language into Japanese in profile
2. Form browser URL location, input below URL, which is not existing

   https://aaa.bbb.com/display/404 
   

Expected Results

"Page Not Found" in Japanese should be return.

Actual Results

It returns a page with garbled characters like below screenshot.

Workaround

Using English as profile language