Q: Share & Markup icons showing but not working (freeze) after upgrade to OS 10.11.5

I have seen posts for Share & Markup options missing after upgrading to Mac OS 10.11.5 (and their Terminal solution).

However I have a different problem: although the Share/Markup icons are visible in Safari/Mail, clicking them makes the program to freeze and forced quit is required to proceed.

I've already tried the mentioned Terminal solution above but that doesn't work.

All sharing/markup options are activated in settings.

Maybe this is related: I've noticed that almost all content that I used to have in Notification Center, such as weather forecast for different locations, is missing, also in the parts section (so it's not a question of reactivating them). Only thing I can do is go to the App Store where I cannot find back the parts I used to have.

Especially the share & markup problem is very annoying!

Thanks for helping me out.

Margo