Exit NinjaTrader
Go into the ‘db’ folder
Rename (or delete) file ‘NinjaTrader.sqlite’
NT will recreate that file next time you startup
This is the ‘nuclear’ option, since it means you’ll
lose all your trade history And all the current
Futures contracts in Tools → Instrument Lists,
so you’ll have to add those back.
All ATMs are stored as XML files elsewhere,
so you won’t lose any of those.