GC NYMEX error message

[bylld4]

Trying to add GC to an Instrument List. All other contracts fine. Add, GC, search, brings up the GC screen (GC Future, GC Stock, GCI, MGC). I click to highlight Future and OK. This returns
"
Assertion Failed: Abort= ...

X no instruments selected, probably a futures with invalid rollover/expiries
"

There is a long series of data after that. What am I doing wrong, and how do I fix it?

Running 8.0.11.1 (Direct)

[NinjaTrader_PatrickG]

I moved your post from an unrelated NinjaTrader 7 post into it's own NinjaTrader 8 post.

Please upgrade to the latest version of NinjaTrader 8 - 8.0.12.0 (this will not remove any of your custom files or settings);

• Close all running applications.
• Uninstall NinjaTrader within Windows Control Panel.
• Navigate to C:\ > Program File (x86) > Delete the 'NinjaTrader 8' folder if it exists
• Reboot your machine.
• Once these steps are completed, download and install NT8 from the link below.
• http://ninjatrader.com/PlatformDirect

When you select GC, does it contain a expiry? For example, GC 04-18. Or does it simply say 'GC' in the instrument field?

Please provide a screenshot of the error you're referring to.