Please describe the problem you are encountering, such as what you are clicking that isn't working.

With Thunderbird 91.13.0 open on my iMac Catalina OS, I click on Address Book.

Address book opens. I scroll down to a particular name and double left click. Up pops Address Book Contact page for that name.

I click on Private and the address information page opens.

I click on the Address line and get a blue line around the address field box.

I mouse over to that block and try to enter data, but the response is as though the keyboard is disconnected.

I cannot enter any new data on that page or any other, eg, Contact, Work, Chat, etc.

It is as thought some other window is open that has taken command of my keyboard entries.

If I go over to the All Address Books on the left margin and click on Personal Address Book or Collected Addresses, I am able to edit information under those lists.

In addition, there are a number of names on the Mac OS X Address Book folder that I would like to delete, but the first 6 items on the Edit menu are greyed out so the Delete Contact option is not available.

Thank you. Roy

Everything is working fine in Windows. We need someone with MAC knowledge to see this thread.