The message says: its seens there is a server issue that prevented Layer slider from saving work. Please Check Layer sliver > system status for potencial errors, try to temporary disable themes / plugins to rule out incompatibility issues or contact your hosting provider to resolve server configuration problems: ERROR HTTP/2.0 403.
My version is 6.3, I update to 6.4 but its doesnt works (i cant edit, save, create a new slide, etc).
I reinstall 6.3 and now this not working (i cant save changes) e says to update to 6.4 (???)
Please, help me.
There is no issue like this present in version 6.3 or 6.4 either, so unfortunately it is most likely a conflict problem on your installation or a server configuration issue.
To start troubleshooting please try to temporary disable other plugins and switch to a default theme to see if that solves the issue.
Please also check the LayerSlider System Status located on the WP sidebar for any related error message.