I am using Microsoft Access 2013, and I am unable to add a new column to a table in Design Mode. I can add a new column in Datasheet Mode, but not in Design.

Hi,
From your description, I tried to do in my computer.
First, I open table1 in  Datasheet Mode.
Rename a neo column.
Second, I right-click table1>Design View>Enter Field Name(Date type)>View> Datasheet View
I find that it works fine.
So I suppose that your Access2013 was damaged.
I recommend that you can use Access2013 in safe mode.
If it works fine in safe mode, you can repair Access2013.
I hope its helps

• Proposed as answer by qian.zhao Wednesday, August 07, 2013 9:50 AM
• Marked as answer by Tony Chen CHNMicrosoft contingent staff, Moderator Thursday, August 15, 2013 8:43 AM

I ran into to the same thing today.

A quick workaround that worked for me was to add the insert columns button to the "Quick Access Toolbar".

After i added a few columns using the Quick access button, the regular (Ribbon) button started working again.