need an advice on OnExecution method during optimalization

[nicknamed]

Hello,
when I optimize my script version 0, all instruments in my instrument list are optimized, but since NT gets unstable and I need the results, then we wrote this logging for each trade which creates separate csv file for each settings of optimization and writes settings for it, So this created version 1, but when I optimize it then only few assets gets optimized (sometimes 5, sometimes 30, but never all 53). All optimizations end with this error:

Error on calling 'OnExecution' method for strategy 'ACEriaV01All/76fddd85b1674fac9a73de8cb8218798': Odkaz na objekt není nastaven na instanci objektu.

Translation:
(Link is not set on object's instance OR Object reference not set to an instance of an object)

This happens sometimes in tens of minutes sometimes after many hours of test running and writing results in csv files (and then when it ends it will show what it has optimized in NT).

Do you have any idea how to solve these unpredictable interruptions of optimization?

May the external connection enabled help (just newest idea which to test would take about 1-2 days and now I want to save precious time by asking)?

Thank you in advance for any tips
N.

[NinjaTrader_RyanM1]

Hello Nicknamed,

We can only suggest the usual debugging approaches here. Use plenty of print statements, and try catch blocks to get more information regarding the error.
Using Try-Catch Blocks

If you have the opportunity, hooking up to the visual studio debugger may be helpful as well.

http://www.ninjatrader.com/support/helpGuides/nt7/visual_studio_debugging.htm

The error message sounds like it's trying to access an invalid object. This article may help with making necessary null reference checks:
Checking for Null References

[nicknamed]

Thanx for the tips, we already tried those tips and so far found nothing that would solve the problem but we will continue in doing that .......