# Sentinel LDK Protection System

**URL:** <https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88>\
**Category:** General\
**Created:** [April 29, 2025, 6:20am UTC](https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88 "2025-04-29T06:20:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Michael](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@Michael](https://nullspaceusers.discourse.group/u/Michael)\
**Post date:** [April 29, 2025, 6:20am UTC](https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88/1 "2025-04-29T06:20:21Z")

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Hello everybody,

as seen in the picture I can’t open NS prep. NS EM i can open but my last simulation also closed at the end with an licence error.

Do you have an idea what the problem is?

> **Error**
>
> ![LDK Protection](https://canada1.discourse-cdn.com/flex010/uploads/nullspaceusers/original/1X/fe8bd96452b8fc69d8c58a585c136a0b901659e3.jpeg)

> **Report.OUT**
>
> main beg
> 
> Failed to login to feature #10: NSEM.
> 
> Error Message: Feature access denied
> 
> License not validated, heartbeat failed to initialize.
> 
> Heartbeat failed to initialize. Rerun with licensing diagnostic for more information.

Best regards

Michael

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**Author:** ![daniel.faircloth](https://yyz2.discourse-cdn.com/flex010/user_avatar/nullspaceusers.discourse.group/daniel.faircloth/32/37_2.png) [@daniel.faircloth](https://nullspaceusers.discourse.group/u/daniel.faircloth)\
**Post date:** [April 29, 2025, 12:04pm UTC](https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88/2 "2025-04-29T12:04:49Z")

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Michael,

This is your computational node and not your laptop, right? Have you tried starting/stopping the license service and/or rebooting? Please send me screenshots from the other tabs in the license control center. From my end, it looks like your license is still valid, so that shouldn’t be the issue. Has anything else changed lately with the configuration of that machine?

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**Author:** ![Michael](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@Michael](https://nullspaceusers.discourse.group/u/Michael)\
**Post date:** [April 29, 2025, 12:48pm UTC](https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88/3 "2025-04-29T12:48:14Z")

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Yes, your right it is on our machine. I can’t restart with my rights the service, so I’ll ask the IT.  
I thought it is a problem with the licence itself.  
Thanks for the fast answer.

Solved!

Under Windows:  
Windows Administrative Tools → Service → Sentinel LDK Protection System  
right click and restart or kill at task manager and start again.  
Admin rights are necessary

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**Author:** ![daniel.faircloth](https://yyz2.discourse-cdn.com/flex010/user_avatar/nullspaceusers.discourse.group/daniel.faircloth/32/37_2.png) [@daniel.faircloth](https://nullspaceusers.discourse.group/u/daniel.faircloth)\
**Post date:** [April 29, 2025, 5:51pm UTC](https://nullspaceusers.discourse.group/t/sentinel-ldk-protection-system/88/4 "2025-04-29T17:51:51Z")

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That’s great. Let me know if you run into anything else.