To remove customizations individually:

The following steps show how to walk through the customizations to Confluence and remove them one by one to determine if one is causing the issue. After removing a piece of customization, retest the issue at hand to see if it has been affected.

 Before removing any customizations, copy it to a text file so it can be easily restored if needed

SITE LEVEL Customizations

• Remove any custom HTML by navigating to Confluence Admin > Custom HTML
• Remove any custom CSS by navigating to Confluence Admin > Custom Stylesheet
• Remove any Layout customizations by navigating to Confluence Admin > Layouts and change any non-default layout to default

You may need to clear your browser cache to see the above changes

 Before removing any customizations, copy it to a text file so it can be easily restored if needed

SPACE LEVEL Customizations

• Remove any space layout customizations by navigating to a Confluence space, then accessing Space Tools > Look & Feel > Layouts and change any non-default layout to default.
• Remove any custom space-level CSS by navigating to a Confluence space, then accessing Space Tools > Look & Feel > Stylesheet

To remove all layouts at once:

The following steps will remove all layout changes to the site. This is a good option to determine immediately if customizations are indeed causing a problem.

Create a full backup of the database before executing the following 

1. Shutdown Confluence
2. (optional) Create a backup of the 'DECORATOR' table

3. Run the following SQL which will delete all layouts applied to the site 

   DELETE from DECORATOR;

4. Start Confluence