How to stop framerate lag due to refiltering when you zone:

Issue: When you zone from an instance to the outside world, the combat log goes through a massive loop, pasting every combat log message in the last 5 minutes.

Why would I want to do this fix?

You have framerate issues when zoning
You have recently been in a combat sessions where there are many combat log events (e.g. raid boss encounters)

Instructions
1. Select the “Everything” tab
2. /script Blizzard_CombatLog_CurrentSettings.settings.showHistory = false

This will prevent all combat log messages from being re-filtered when you zone.

Side-Effects
This will also prevent you from seeing old messages with the “Everything” tab.

How to Undo
If you accidentally set this on the wrong tab, select the broken tab and type:
/script Blizzard_CombatLog_CurrentSettings.settings.showHistory = true

These settings will be saved when you logout.