The alerts tab shows alerts generated by Burp's tools. This information may be useful to troubleshoot network connection or other problems.
If the same alert is generated more than once in succession, the alerts are consolidated into a single entry in the table, with a counter showing the number of times the alert was generated.
Get help from other users, at the Burp Suite User Forum:
This release adds support for WebSockets to the Proxy tool. You can now view, intercept and modify WebSockets messages in the same way as regular HTTP messages.
The Scanner's support for nested insertion points has been updated to support nested data in URL-encoded query string format and precise highlighting of relevant syntax in reported Scanner issues.