# Using Command Expert with OpenTAP

**URL:** <https://forum.opentap.io/t/using-command-expert-with-opentap/138>\
**Category:** Ecosystem\
**Tags:** plugin, faq, ks8400-editor\
**Created:** [November 25, 2020, 6:58pm UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138 "2020-11-25T18:58:01Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![kaushik.santhanam](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opentap.io/kaushik.santhanam/32/208_2.png) [@kaushik.santhanam](https://forum.opentap.io/u/kaushik.santhanam)\
**Post date:** [November 25, 2020, 6:58pm UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/1 "2020-11-25T18:58:01Z")

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A free Command Expert plugin is provided here at [https://packages.opentap.io/index.html#/?name=CommandExpert](https://packages.opentap.io/index.html#/?name=CommandExpert)  
Once installed, you can find the usage documentation in the `<tap installation path>/CommandExpertHelp.chm` file

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**Author:** ![jeff.dralla](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opentap.io/jeff.dralla/32/220_2.png) [@jeff.dralla](https://forum.opentap.io/u/jeff.dralla)\
**Post date:** [November 25, 2020, 8:11pm UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/2 "2020-11-25T20:11:37Z")

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Here’s a helpful tutorial on Command Expert!

[![](https://us1.discourse-cdn.com/flex020/uploads/opentap/original/1X/834cf02f1efbec3563785d5e17e7ad8e2fe91f06.jpeg "Easy instrument programming with Command Expert Tutorial") ](https://www.youtube.com/watch?v=nHSU6RjHCqE)

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**Author:** ![hongbo.huo](https://avatars.discourse-cdn.com/v4/letter/h/67e7ee/32.png) [@hongbo.huo](https://forum.opentap.io/u/hongbo.huo)\
**Post date:** [July 19, 2021, 6:52am UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/3 "2021-07-19T06:52:40Z")

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when tried the command expert. The test step reports an error :" 14:49:34.845 TestStep Failed to create teststep from sequence file: Value cannot be null.  
Parameter name: path1"  
The command is very simple only with a “CLS” command.  
Could anyone tell me how to use this correctly? thanks

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**Author:** ![brennen\_direnzo](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opentap.io/brennen_direnzo/32/6_2.png) [@brennen\_direnzo](https://forum.opentap.io/u/brennen_direnzo)\
**Post date:** [July 19, 2021, 3:16pm UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/4 "2021-07-19T15:16:03Z")

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@hongbo.huo can you share your configuration in Command Expert and your Test Plan? Attached is doc that shows more detail on how to use the Command Expert plugin.  
[OpenTAP Training 3 - Non-Programmer Lab.pdf](https://forum.opentap.io/uploads/short-url/pLwLxxpHELLvhG0pqKoqQVreWYw.pdf) (1.9 MB)

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**Author:** ![hongbo.huo](https://avatars.discourse-cdn.com/v4/letter/h/67e7ee/32.png) [@hongbo.huo](https://forum.opentap.io/u/hongbo.huo)\
**Post date:** [July 20, 2021, 12:33am UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/5 "2021-07-20T00:33:02Z")

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@brennen_direnzo It’s win7 32bit computer, commandexpert version was 1.8, openTap version was 9.15. I tried win10+command expert 1.9+ openTap 9.15. This works perfectly.  
Maybe command expert version 1.8 was too old

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**Author:** ![brennen\_direnzo](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opentap.io/brennen_direnzo/32/6_2.png) [@brennen\_direnzo](https://forum.opentap.io/u/brennen_direnzo)\
**Post date:** [July 20, 2021, 12:52am UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/6 "2021-07-20T00:52:47Z")

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Yes, my next suggestion was going to be make sure you have the latest version of Command Expert. I believe 1.9 is required.

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**Author:** ![jmuthu89](https://avatars.discourse-cdn.com/v4/letter/j/13edae/32.png) [@jmuthu89](https://forum.opentap.io/u/jmuthu89)\
**Post date:** [July 19, 2022, 11:20am UTC](https://forum.opentap.io/t/using-command-expert-with-opentap/138/7 "2022-07-19T11:20:12Z")

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@kaushik.santhanam same error msg i am also getting  
**Failed to create Test step from Sequence File: value cannot be null .Parameter name: Path1,**

i installed latest version of Command Expert 1.10.50.

Suggest me how to resolve this error.