Issue Summary

Bitbucket invalid URLs contain a link to go to the previous page. This link function is currently "javascript:window.history.back". 

However, this is outdated and browsers may block it in the future leading to undesired results. It is also not recommended due to security and accessibility concerns. 

The right approach would be to use "<a href="#" onclick="window.history.back(); return false;">previous page</a>" instead of "<a href="javascript:window.history.back()">previous page</a>".