NinjaTrader 7 scripts are not compatible with NinjaTrader 8, which means NinjaTrader 7 script will not work in NinjaTrader 8.
If you would like your indicators and strategies to continue working in NT8 you would have to go through code upgrade process. That's right, you will have one script for NinjaTrader 7 and another one for NinjaTrader 8.
We have been converting NinjaTrader7 scripts to NinjaTrade8 from the day 1. Trading indicators, automated strategies, drawing tools, custom rendering, chart and menu integrations, and much more.
Ask for a Free Quote, we will be happy to help!
Please have a look at this PDF-document on NinjaTrader website that captures all major improvements in NT8.
In a nutshell - it's a big step ahead!