# “Launch client jar signature is invalid” 8.1.51

**URL:** <https://forum.inductiveautomation.com/t/launch-client-jar-signature-is-invalid-8-1-51/117671>\
**Category:** Ignition\
**Tags:** vision, ignition81\
**Created:** [October 29, 2026, 11:09pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-signature-is-invalid-8-1-51/117671 "2026-10-29T23:09:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![n099y](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@n099y](https://forum.inductiveautomation.com/u/n099y)\
**Post date:** [October 29, 2026, 11:09pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-signature-is-invalid-8-1-51/117671/1 "2026-10-29T23:09:21Z")

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I have this error "Launch client jar invalid" "This launch client jar signature is invalid. Contact an administrator."

 ![](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/2/62fc884089825b0591f7e552edb2e395a7e5efbc.png)

I have seen the other threads and they are not my issue, I have tried all of those solutions.

This is an Intune Windows Machine. I have this working on another machine exactly the same and I cannot remember how. Is anyone able to help me out here ?

> **Click to view full Java exception log**
>
> ```python
> INFO [GatewayCommUtil] [2026/10/30 09:02:29]: Downloading "http://my.company.webaddress/system/launchbin/launchclient.jar" (timeout=30)...
> INFO [GatewayCommUtil] [2026/10/30 09:02:29]: Starting download of 6844145 bytes
> ERROR [LaunchClientJarService] [2026/10/30 09:02:30]: Launch client jar Invalid
> java.net.SocketException: Connection reset
> at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:328)
> at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:355)
> at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:808)
> at java.base/java.net.Socket$SocketInputStream.read(Socket.java:976)
> at java.base/java.io.BufferedInputStream.read1(BufferedInputStream.java:282)
> at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:343)
> at java.base/sun.net.www.MeteredStream.read(MeteredStream.java:141)
> at java.base/java.io.FilterInputStream.read(FilterInputStream.java:132)
> at java.base/sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:3763)
> at java.base/java.io.FilterInputStream.read(FilterInputStream.java:132)
> at com.inductiveautomation.ignition.launcher.common.utils.Crc32InputStream.read(Crc32InputStream.java:32)
> at java.base/java.io.FilterInputStream.read(FilterInputStream.java:106)
> at com.inductiveautomation.ignition.launcher.common.utils.GatewayCommUtil.downloadFile(GatewayCommUtil.java:584)
> at com.inductiveautomation.ignition.launcher.common.service.LaunchClientJarService$LaunchClientJarTask.lambda$downloadLaunchClientJar$3(LaunchClientJarService.java:362)
> at com.inductiveautomation.ignition.launcher.common.utils.FileUtils.runResourceLockedAction(FileUtils.java:110)
> at com.inductiveautomation.ignition.launcher.common.service.LaunchClientJarService$LaunchClientJarTask.downloadLaunchClientJar(LaunchClientJarService.java:360)
> at com.inductiveautomation.ignition.launcher.common.service.LaunchClientJarService$LaunchClientJarTask.getLaunchClientJar(LaunchClientJarService.java:227)
> at com.inductiveautomation.ignition.launcher.common.service.LaunchClientJarService$LaunchClientJarTask.call(LaunchClientJarService.java:167)
> at com.inductiveautomation.ignition.launcher.common.service.LaunchClientJarService$LaunchClientJarTask.call(LaunchClientJarService.java:139)
> at javafx.concurrent.Task$TaskCallable.call(Task.java:1426)
> at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
> at javafx.concurrent.Service.lambda$executeTask$6(Service.java:728)
> at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
> at javafx.concurrent.Service.lambda$executeTask$7(Service.java:727)
> at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
> at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
> at java.base/java.lang.Thread.run(Thread.java:840)
> 
> ```

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [October 30, 2026, 12:02am UTC](https://forum.inductiveautomation.com/t/launch-client-jar-signature-is-invalid-8-1-51/117671/2 "2026-10-30T00:02:28Z")

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> [@n099y](#):
>
> `java.net.SocketException: Connection reset`

That is an interrupted jar download. Typically anti-virus or similar anti-malware. Sorry, but this is induced outside Ignition.

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<div class="post-metadata">

**Author:** ![n099y](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@n099y](https://forum.inductiveautomation.com/u/n099y)\
**Post date:** [October 30, 2026, 12:28am UTC](https://forum.inductiveautomation.com/t/launch-client-jar-signature-is-invalid-8-1-51/117671/3 "2026-10-30T00:28:56Z")

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Yeah, I had been down that track, it actually did come from ignition in the end last time. The log is not much use at all.  
Its got something to do with ignition not liking the way the Intune PC's work. I had to change a setting in the config. But of course, I did not record my findings last time and now I am hoping someone has had a similar issue.