# Dragonfly\_mapper\_measure example failed to run

**URL:** <https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814>\
**Category:** dragonfly\
**Tags:** measures\
**Created:** [September 28, 2026, 9:39pm UTC](https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814 "2026-09-28T21:39:19Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![behnammmohseni](https://discourse.ladybug.tools/letter_avatar_proxy/v4/letter/b/c68b51/32.png) [@behnammmohseni](https://discourse.ladybug.tools/u/behnammmohseni)\
**Post date:** [September 28, 2026, 9:39pm UTC](https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814/1 "2026-09-28T21:39:19Z")

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Hi everyone,  
@chris

I recently tried to have mapper example simulation using add\_EV\_load in Dragonfly.

It seems there is a problem in the OSM measures:

 ![image](https://discourse.ladybug.tools/uploads/default/original/3X/8/c/8c3712bfcd659da019bd5d685a283e72f8ff8cf5.jpeg)

and here is the run log errors:

[22:22:38.806924 ERROR] [openstudio.WorkflowJSON] OpenStudio measure ‘Add\_EV\_Load’ called after transition to EnergyPlus.  
[22:22:38.866371 FATAL] [openstudio.workflow.OSWorkflow] Workflow is invalid  
[22:22:38.866371 ERROR] [openstudio.workflow.OSWorkflow] Found error in state ‘Initialization’ with message: ‘D:\a\OpenStudio\OpenStudio\OpenStudio\src\workflow\RunInitialization.cpp@63 : Workflow is invalid’

I also tried to use add\_rooftop\_pv in HB tools, and it seems the simulation is not running.

Could you kindly let me know how I can address these challenges?

Sincerely,  
Behnam

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**Author:** ![chris](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/chris/32/10179_2.png) [@chris](https://discourse.ladybug.tools/u/chris)\
**Post date:** [September 28, 2026, 10:27pm UTC](https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814/2 "2026-09-28T22:27:15Z")

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Thanks, @behnammmohseni .

The failure to run mapper measures is a bug that I should be able to fix shortly. Will post back here when it is fixed.

I am not sure what `add_rooftop_pv` refers to.

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**Author:** ![chris](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/chris/32/10179_2.png) [@chris](https://discourse.ladybug.tools/u/chris)\
**Post date:** [September 28, 2026, 11:20pm UTC](https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814/3 "2026-09-28T23:20:08Z")

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I fixed the bug here:

> <https://github.com/ladybug-tools/dragonfly-energy/pull/943>

.. and you can now get the fix via the LB Versioner.

Thanks again for reporting, @behnammmohseni .

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<div class="post-metadata">

**Author:** ![behnammmohseni](https://discourse.ladybug.tools/letter_avatar_proxy/v4/letter/b/c68b51/32.png) [@behnammmohseni](https://discourse.ladybug.tools/u/behnammmohseni)\
**Post date:** [September 29, 2026, 5:05am UTC](https://discourse.ladybug.tools/t/dragonfly-mapper-measure-example-failed-to-run/40814/4 "2026-09-29T05:05:26Z")

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Thank you very much @chris

The simulation works now in UrbanOpt and Dragonfly environment.

add\_rooftop\_pv is a Ruby measure that you can assign the percentage of the rooftop to be cover by PV. For large scale simulation (more than thousand buildings), it ease many challenges.

However, for the Honeybee Openstudio engine there is a problem index below:

 ![image](https://discourse.ladybug.tools/uploads/default/original/3X/d/c/dc844a4146d99783b362ab5f6eed6536f5b4a1d7.jpeg)

[06:29:26.834892 ERROR] [openstudio.WorkflowJSON] Cannot find measure ‘add\_rooftop\_pv’  
[06:29:26.834892 FATAL] [openstudio.workflow.OSWorkflow] Workflow is invalid  
[06:29:26.834892 ERROR] [openstudio.workflow.OSWorkflow] Found error in state ‘Initialization’ with message: ‘D:\a\OpenStudio\OpenStudio\OpenStudio\src\workflow\RunInitialization.cpp@63 : Workflow is invalid’

Could you kindly let me know how I can address this challenge?

Sincerely,  
Behnam