# Error starting ARsim - no valid signature ar000.exe

**URL:** <https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789>\
**Category:** B&R Software & Runtime\
**Tags:** arsim\
**Created:** [July 2, 2026, 10:38am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789 "2026-07-02T10:38:44Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Jurgen\_Weber](https://avatars.discourse-cdn.com/v4/letter/j/FF8800/32.png) [@Jurgen\_Weber](https://community.br-automation.com/u/Jurgen_Weber)\
**Post date:** [July 2, 2026, 10:38am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789/1 "2026-07-02T10:38:44Z")

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With AS6.5.3.11 I have that problem that B&R Automation studio only build the ArSim directory ok.

Here ok

02-07-2026 12:28:39 - COPYRIGHT (C) B&R Industrial Automation GmbH  
02-07-2026 12:28:39 - No ARsim registration found!  
02-07-2026 12:28:39 - InstanceName: 0000001c8db014e5  
02-07-2026 12:28:39 - WorkingDirectory: D:\Ersa\SPS\KE.ON\Net10Update\PLC\Machine\Temp\Simulation\Testrack\_Orange\5APC2200\_AL04\_000  
02-07-2026 12:28:39 - COMMAND\_COLDSTART  
02-07-2026 12:28:42 - Version: 6.7.6  
02-07-2026 12:28:42 - Build: 1  
02-07-2026 12:28:44 - COMMAND\_TERMINATE  
02-07-2026 12:28:44 - COMMAND\_COLDSTART  
02-07-2026 12:28:46 - Version: 6.7.6  
02-07-2026 12:28:46 - Build: 1  
02-07-2026 12:33:20 - COMMAND\_TERMINATE

Here not ok

02-07-2026 12:33:22 - COPYRIGHT (C) B&R Industrial Automation GmbH  
02-07-2026 12:33:22 - No ARsim registration found!  
02-07-2026 12:33:22 - InstanceName: 0000001d363d07c1  
02-07-2026 12:33:22 - WorkingDirectory: D:\Ersa\SPS\KE.ON\Net10Update\PLC\Machine\Temp\Simulation\Testrack\_Orange\5APC2200\_AL04\_000  
02-07-2026 12:33:22 - COMMAND\_COLDSTART  
02-07-2026 12:33:22 - Error starting ARsim - no valid signature ar000.exe

If I look in the folder I miss for example the file ar000.exe.

Firewall switch off

Virus protection switch off

With older version AS6 I have not this problem.

Can somebody help or have the same issue.

Best regards Jürgen

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**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\
**Post date:** [July 2, 2026, 10:45am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789/2 "2026-07-02T10:45:15Z")

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Hi @Jurgen_Weber ,  
R&D is working on that. We can only propose this step in case you(we, I have the same issue) face again that issue: _“Delete the ArSim Temp folder or to perform another Offline Installation”_

Ciao  
Valerio

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**Author:** ![Samuel](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/samuel/32/155_2.png) [@Samuel](https://community.br-automation.com/u/Samuel)\
**Post date:** [July 2, 2026, 10:54am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789/3 "2026-07-02T10:54:08Z")

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Or simply reinstall the ARsim (Alt+F8). In my case, that usually helped.

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<div class="post-metadata">

**Author:** ![Jurgen\_Weber](https://avatars.discourse-cdn.com/v4/letter/j/FF8800/32.png) [@Jurgen\_Weber](https://community.br-automation.com/u/Jurgen_Weber)\
**Post date:** [July 2, 2026, 11:07am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789/4 "2026-07-02T11:07:06Z")

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Thank you.

I can work at the moment. But no solution for all time. I wait then for solution from B&R

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<div class="post-metadata">

**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\
**Post date:** [July 2, 2026, 11:09am UTC](https://community.br-automation.com/t/error-starting-arsim-no-valid-signature-ar000-exe/11789/5 "2026-07-02T11:09:12Z")

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I mark the solution, the answer I gave to you and I’ll update the post once I’ll receive the fix.

Ciao  
Valerio