# I am getting a blocking error in the SimScale Workbench stating 'This name is not allowed' when renaming entities for my CHT simulation, and I need help identifying which name is causing the block

**URL:** <https://www.simscale.com/forum/t/i-am-getting-a-blocking-error-in-the-simscale-workbench-stating-this-name-is-not-allowed-when-renaming-entities-for-my-cht-simulation-and-i-need-help-identifying-which-name-is-causing-the-block/101317>\
**Category:** Project Support\
**Created:** [September 1, 2026, 4:24pm UTC](https://www.simscale.com/forum/t/i-am-getting-a-blocking-error-in-the-simscale-workbench-stating-this-name-is-not-allowed-when-renaming-entities-for-my-cht-simulation-and-i-need-help-identifying-which-name-is-causing-the-block/101317 "2026-09-01T16:24:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![crithelion](https://www.simscale.com/forum/letter_avatar/crithelion/32/5_5575768a8748004e209b776fc1b2916d.png) [@crithelion](https://www.simscale.com/forum/u/crithelion)\
**Post date:** [September 1, 2026, 4:24pm UTC](https://www.simscale.com/forum/t/i-am-getting-a-blocking-error-in-the-simscale-workbench-stating-this-name-is-not-allowed-when-renaming-entities-for-my-cht-simulation-and-i-need-help-identifying-which-name-is-causing-the-block/101317/1 "2026-09-01T16:24:38Z")

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```auto
Hi SimScale Community,

I am a student currently working on a Conjugate Heat Transfer (CHT) simulation of an apartment to analyze indoor thermal comfort and the effectiveness of a Mechanical Ventilation (VMC) system.

**The Issue:**
I am encountering a blocking validation error in the Workbench tree that prevents me from starting my simulation or saving a setup. The error message is:
*"This name is not allowed. The name must start with a letter or parenthesis, followed by letters, parentheses, numbers, spaces or -, +, _. Also make sure that the length of the name does not exceed 200 characters."*

I suspect this is related to how I named one of my boundary conditions, materials, or possibly because of the body names transferred during the CAD import from Onshape/Revit. 

**What I have checked so far:**
- I tried to avoid using Italian accented letters (like à, è, é, ì, ò, u) in my boundary conditions and materials.
- I checked if any name starts with a number.
- I am looking for other potential illegal characters (like dots "." in U-values, or degree symbols "°" in temperature references, e.g., "30°C") but I am struggling to pinpoint which specific entity is triggering the validation block.

Could you please help me identify which name is causing this conflict in my project tree?

**Project Link (Share with Support is enabled):**
https://www.simscale.com/workbench/?pid=5468379227574173171&mi=spec:0ef64d01-c0e6-46ae-8312-43e85976d241%2Cservice:SIMULATION%2Cstrategy:25&ps=analysis%2FresultControl%2FprobePoints%2F0

Thank you in advance for your help!
![errors-screen01|690x352](upload://6CnPElzsQNtVk0nTWciA3b9Gp59.png)
![errors-screen02|690x299](upload://b2ybTdzyGE4mbfK55HE3sJw43R1.png)
```

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<div class="post-metadata">

**Author:** ![RicardoParis](https://www.simscale.com/forum/user_avatar/www.simscale.com/ricardoparis/32/30222_2.png) [@RicardoParis](https://www.simscale.com/forum/u/RicardoParis)\
**Post date:** [September 1, 2026, 4:28pm UTC](https://www.simscale.com/forum/t/i-am-getting-a-blocking-error-in-the-simscale-workbench-stating-this-name-is-not-allowed-when-renaming-entities-for-my-cht-simulation-and-i-need-help-identifying-which-name-is-causing-the-block/101317/3 "2026-09-01T16:28:53Z")

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Hi,

There is a dot “.” in the name of a probe point. So “SONDA TEMP.” is not going to work, but “SONDA TEMP” would work.

 ![image](https://www.simscale.com/forum/uploads/default/original/3X/8/a/8ab812e07afdd686de081f21c1fcca8ac82e3c36.png)