# Running into "HDF proxy missing" exception with C# library

**URL:** <https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186>\
**Category:** FESAPI\
**Created:** [October 22, 2021, 5:05am UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186 "2021-10-22T05:05:02Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![sgthomas-github](https://discourse.f2i-consulting.com/user_avatar/discourse.f2i-consulting.com/sgthomas-github/32/12_2.png) [@sgthomas-github](https://discourse.f2i-consulting.com/u/sgthomas-github)\
**Post date:** [October 22, 2021, 5:05am UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186/1 "2021-10-22T05:05:02Z")

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Hi all,  
We are using the FesapiCs0.13.0.0 Version=0.13.0.0 assembly for C# but when trying to specify the parent window for LGR using the `setParentWindow` API in `AbstractGridRepresentation`, I am running into a runtime exception `HDF proxy is missing`, even though HDF proxy is defined on the EPC document. Also I noted that the `AbstractRepresentation` class for C# assembly is missing the `setHdfProxy` API which is found for C++ libs. Is this expected and if so, is there any workaround that could help me to resolve this?  
Thank you,  
-Sunil.

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**Author:** ![philippeVerney](https://discourse.f2i-consulting.com/user_avatar/discourse.f2i-consulting.com/philippeverney/32/29_2.png) [@philippeVerney](https://discourse.f2i-consulting.com/u/philippeVerney)\
**Post date:** [October 22, 2021, 8:44am UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186/2 "2021-10-22T08:44:09Z")

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Hi,

v0.13.0.0 is an old version. You should consider upgrading your FESAPI.  
At a first glance, it looks this bug has been solved from [v0.16.0.0](https://github.com/F2I-Consulting/fesapi/releases/tag/v0.16.0.0) which you should be able to adopt easily. A shift to v1 and even v2 would be even better but would require more development.

In v0.13.0.0, the hdf proxy associated to the LGR must be set somehow **before** to call `setParentWindow`. For example, setting the geometry of the LGR **before** to set its parent window should do the desired workaround. Indeed, in the various setGeometry methods, you often can set the HdfProxy as a parameter.

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**Author:** ![philippeVerney](https://discourse.f2i-consulting.com/user_avatar/discourse.f2i-consulting.com/philippeverney/32/29_2.png) [@philippeVerney](https://discourse.f2i-consulting.com/u/philippeVerney)\
**Post date:** [October 22, 2021, 8:49am UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186/3 "2021-10-22T08:49:50Z")

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FYI, and for tracability reason, here is the commit which should fix this issue : [Support for multirealization properties by philippeVerney · Pull Request #149 · F2I-Consulting/fesapi · GitHub](https://github.com/F2I-Consulting/fesapi/pull/149/commits/20befcab84590de238efa358009e0530fb329047)

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**Author:** ![sgthomas-github](https://discourse.f2i-consulting.com/user_avatar/discourse.f2i-consulting.com/sgthomas-github/32/12_2.png) [@sgthomas-github](https://discourse.f2i-consulting.com/u/sgthomas-github)\
**Post date:** [October 26, 2021, 11:23pm UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186/4 "2021-10-26T23:23:43Z")

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Hi Philippe, thanks for the responses, and I just wanted to update you that I installed the tag 0.16.0.0 and confirm that it fixes the exception issue.

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**Author:** ![sgthomas-github](https://discourse.f2i-consulting.com/user_avatar/discourse.f2i-consulting.com/sgthomas-github/32/12_2.png) [@sgthomas-github](https://discourse.f2i-consulting.com/u/sgthomas-github)\
**Post date:** [November 13, 2024, 8:30pm UTC](https://discourse.f2i-consulting.com/t/running-into-hdf-proxy-missing-exception-with-c-library/186/5 "2024-11-13T20:30:16Z")

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Hi, I keep running into an exception with v0.13 on C++ when using the setParentWindow API about invalid argument even though I confirmed from debugging that all the arguments passed are correct types and sizes. Is this a known issue as well like the previous one and will it be fixed if I updated to 0.16.0.0? I am trying the workaround you described in the interim.

EDIT: Looks like the workaround worked fine, thank you!