i have upgraded to Ubuntu 24.04 + ungraded my ubuntu-mate package to 1.26.2.
But now i have no notification area (= that little area on the panel bar where you will see the icons from nextcloud, dropbox, wifi, email-counter, etc) on the "status bar" and when i try to add it to the panel just nothing happens.
When you right-click on the panel try and select "Add to Panel" option and then scroll and select "Indicator Applet Complete" - it should add you all those little indicators with notification applet included - notification applet is that one that looks like a bell - right next to connections indicator and left of battery indicator