sometimes it is best to just start over!
To delete all of your existing chart templates, BROWSE TO Documents\NinjaTrader 7 (8)\templates\Chart and then delete them all.
You may also wish to delete all of your workspaces. BROWSE COMPUTER TO search to Documents\NinjaTrader 7 (8)\workspaces and DELETE EVERY FILE.
To download current software, visit Nexgen's resource page on the website https://nexgent3.com/resources/ and download the current workspaces and templates. Once complete, open Ninja Trader and enjoy your fresh workspaces.