This was an issue several colleagues were dealing with, with seemingly no explanation or resolution.

Simply connecting to the IQFeed data would cause NinjaTrader to lock/freeze and require a force stop.

It was finally discovered this was due to a port conflict with the IQFeed client software. Uninstalling or disabling any other program running on your computer that uses port 9100 should resolve this issue.

A known example of this is Logitech G Hub (GHub).

This took quite some time and headache to diagnose, and surprisingly is not mentioned here, and DTN Support does not seem aware of this issue. So I figured having this post here might help some folks in the future.

DTN Support is well aware of this issue, since it is a port confliction the only current solution is to remove or disable Ghub. A more satisfactory solution has been investigated. At this time there is no update available regarding a resolution.

Another solution that does not require disabling Logitech's Ghub is to change IQFeed's LookupPort from 9100 to some other number that is not used by any other program on your computer (e.g. 9110). You can do this by modifying the LookupPort value in the Windows registry (HKEY_CURRENT_USER\Software\DTN\IQFeed\Startup), using Windows' Registry Editor program. If IQConnect is running, you will need to restart it for the new value to take effect.

A previous post about this issue can be found here: http://forums.dtn.com/index.cfm?page=topic&topicID=5843

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Yair Altman
IQML - IQFeed-MATLAB connector
https://UndocumentedMatlab.com/IQML

I am not a DTN employee; my post reflects my personal opinion
Edited by altmany on Apr 13, 2023 at 03:35 AM

Yair is correct, but I warn that changing the Lookup/History port from 9100 to something else can cause third-party apps not to work. They may assume the port is 9100, instead of confirming it in the registry first.

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Sincerely,
Gary Stephen
DTN IQFeed Implementation Support Specialist