# Designer launcher failed to launch

**URL:** <https://forum.inductiveautomation.com/t/designer-launcher-failed-to-launch/115231>\
**Category:** Ignition\
**Created:** [April 24, 2026, 9:16am UTC](https://forum.inductiveautomation.com/t/designer-launcher-failed-to-launch/115231 "2026-04-24T09:16:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Elias\_Ghadbane](https://avatars.discourse-cdn.com/v4/letter/e/e68b1a/32.png) [@Elias\_Ghadbane](https://forum.inductiveautomation.com/u/Elias_Ghadbane)\
**Post date:** [April 24, 2026, 9:16am UTC](https://forum.inductiveautomation.com/t/designer-launcher-failed-to-launch/115231/1 "2026-04-24T09:16:35Z")

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Hello, I need advice on this issue. I’ve tried multiple solutions, including deleting the folder in AppData\Roaming\Ignition and clearing the cache at `C:\Users\elias.ignition\clientlauncher-data`, but the error still persists.

 ![Screenshot 2026-04-24 115646](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/c/dc9e041259b685691482b500ec8bbb6b7670c42d.png)

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**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:** [April 24, 2026, 1:08pm UTC](https://forum.inductiveautomation.com/t/designer-launcher-failed-to-launch/115231/2 "2026-04-24T13:08:15Z")

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Read this entire topic, particularly near the end where LENIENT mode is discussed:

> [@Unable to start Designer or Client ERROR "This Launch Jar Signature is invalid. Contact an administrator"](https://forum.inductiveautomation.com/t/unable-to-start-designer-or-client-error-this-launch-jar-signature-is-invalid-contact-an-administrator/96092):
>
> Hello I have been using ignition for awhile. I recently uploaded my files to an IPC in my control panel. It was working great for a few days until about an hour ago. I have been getting the error every time I try to launch a project in both the designer and client . "This Launch Jar Signature is invalid. Contact an administrator". I have cycled powered, reinstalled ignition designer and client and deleted all my files inside the .ignition folder under users. I am stumped on what to try next. Tha…

FWIW, this simple search led to the above discussion:

[https://forum.inductiveautomation.com/search?q=designer%20signature%20invalid%20order%3Alatest](https://forum.inductiveautomation.com/search?q=designer%20signature%20invalid%20order%3Alatest)