# Launch Client Jar Invalid Error

**URL:** <https://forum.inductiveautomation.com/t/launch-client-jar-invalid-error/115993>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [June 16, 2026, 12:24am UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid-error/115993 "2026-06-16T00:24:19Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Arnaud\_Declerck](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/arnaud_declerck/32/44872_2.png) [@Arnaud\_Declerck](https://forum.inductiveautomation.com/u/Arnaud_Declerck)\
**Post date:** [June 16, 2026, 5:43am UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid-error/115993/2 "2026-06-16T05:43:38Z")

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Hi @farjam_haghighi ,

I think this would help you

> [@Launch client jar invalid](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145):
>
> Testing Ignition 8.3.0 Beta. I had to upgrade my Designer Launcher to 1.3.0 Beta-1 to access the 8.3 designer. However, I'm now unable to open any of my other 8.1.23 designers; I receive a "Launch client jar invalid" message. I ended up downgrading my designer, but this means I can no longer access 8.3. Has anyone else encountered this issue?

Regards

Arnaud

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