You try to access a list view, and…
When a List View is timing out, it’s usually caused lack of criteria, which is making the query look through too many records.
Here’s how to get into edit mode and fix it.
1) Make a note of two list view names, the one you’re trying to fix, and any other that is working.
2) On your Object page, right click and ‘view page Source
3) In that code, there will be a section of your list views with their names and ID’s. Copy the ID of the broken List View
4) Go back to Object Page, open a working list View, and click Edit.
5) In the URL, replace the ID of the working list view with the broken list view, then hit Enter.
6) You’re now in edit mode of your broken list view. From here, you can make the changes needed to prevent it from timing out.