# Ignition launch client jar invalid how to fix

**URL:** <https://forum.inductiveautomation.com/t/ignition-launch-client-jar-invalid-how-to-fix/105644>\
**Category:** Ignition\
**Tags:** ignition81, ignition79, ignition80\
**Created:** [April 28, 2025, 6:35pm UTC](https://forum.inductiveautomation.com/t/ignition-launch-client-jar-invalid-how-to-fix/105644 "2025-04-28T18:35:49Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [April 28, 2025, 6:38pm UTC](https://forum.inductiveautomation.com/t/ignition-launch-client-jar-invalid-how-to-fix/105644/2 "2025-04-28T18:38:39Z")

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This thread has a lot of troubleshooting options and solutions, but I'm linking specifically to a post with directions on how to get detailed logs to start troubleshooting: [Unable to start Designer or Client ERROR "This Launch Jar Signature is invalid. Contact an administrator" - #6 by Kevin.Herron](https://forum.inductiveautomation.com/t/unable-to-start-designer-or-client-error-this-launch-jar-signature-is-invalid-contact-an-administrator/96092/6)

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