If you cant get into Edit mode to manipulate the page because of a bad module, you may have to resolve the problem by removing modules from the page by hand directly in the database. But be sure to know what you are doing, you could mess things more up here.
If you know the TabId of the page you are having trouble with you can isolate the active modules in the page by running this query f.ek., through MS Sql management studio or similar tool, (where 117 is an example tabid):
select * from TabModules where TabId = 117 and IsDeleted = 'False'
Now copy the "TabModuleID" column into notepad... keeping all the Ids of active Tab modules in the page on the side.
Now run this update to disable all modules in the page:
update TabModules set IsDeleted = 'True' where TabId = 117 and IsDeleted = 'False'
Now open a command window on the server and run IISreset
(to clear up all cached data).
Then open the problem page in the webbrowser. Now you hopefully have a running page, but missing all the modules.
Now add the modules back, one by one, by running this update for each of the ids you saved into notepad:
update TabModules set IsDeleted = False where TabId = 117 and IsDeleted = False
and TabModuleId = 99
(here 99 represents one of the TabModuleIds you saved on the side in notepad).
Refresh the page in between updates to see the modules come back. Its possible you have to run IISreset in between too to see changes.
When the page fails again, you have found the bad module. Disable it again by changing IsDeleted = 'False' to 'True'.
Add the remaining modules.