I've had the same problem that many of you have had with the JMR-2023 Update - it won't recopgnize my license key.
On 05-05-2023 I received an email from Jaksta support:
Your activation code will remain valid for all future
versions of Jaksta for Windows.
Therfore, no new license should be necessary.
The following steps worked for me to reinstall JMR-2022.3.13.0 for Windows after the JMR-2023 update failure.
PLEASE NOTE: Thhis assumes you have a copy of JMR-2022.3.13.0.exe
1. Completeley uninstall JMR-2023. i used Geek Uninstaller to do this.
a) JMR-2023 has 3 components; NPcap, NetMonitor, and JMR-2023. I uninstalled NeMonitor and NPCap first, then JMR-2023.
2. If you still have JMR-2022.3.13.0 installed, try it. If it works, great. If not, proceed to step 3.
3. Completeley uninstall JMR-2022.3.13.0 (see step 1, Geek Uninstaller)
4. Reboot, then reinstall JMR-2022.3.13.0 (if you have it).
This procedure recovered JMR-2022.3.13.0, and my old license key worked. Until they get JMR-2023 fixed, I suggest you go to the "Get Support" tab in JMR-2022 and set "Check for new version on start" to OFF.
Hope this helps.