"Launch client jar signature is invalid" error

Ignition
2

Hey I might be completly off with this, but it looks like you have a similar issue to something mentioned on this post. Not sure of the details, but has the same error you have, so it might work.

Unable to start Designer or Client ERROR "This Launch Jar Signature is invalid. Contact an administrator" - #15 by jcoffman

They also mentioned this: Launchers and Workstation | Ignition User Manual