Solex TX isn't responding

Went to fly yesterday but got this error on my Herelink any idea?

Did you open both QGC and Solex on the Herelink?
They may be conflicted if other one of them is still running in background.

No, I only use Solex

Do a full refresh of the firmware this usually resolved the issue.

What do you mean? Re-update it?

I think that’s what he mean.
https://docs.cubepilot.org/user-guides/herelink/herelink-user-guides/upgrading-firmware

Before re-updating, you may try to reset the controller to factory from the setting page. It is slightly easier if this works.