Redmond doesn't work

[vr_anticipator]

I solved the problem:

Clock and weather disappeared from top panel. Can't restore them

I just started using Mate on my Raspberry Pi2. Today I noticed all the notifications (clock, weather etc) have disappeared from my top panel. I got a message on-screen saying Ubuntu Mate has experienced a problem related to the panel. I tried to add everything back using [right click][add to panel] but that doesn’t work. Can anyone help? Is this a known issue?