Unable to use Text Box

Several toolbars are wholly or partially "greyed out" (inactive). For
instance, Drawing toolbar allows me to use Fill Colour & Line Colour & Font
Colour but NOT to use Text Box, Connectors, Auto Shapes and others.
Odd thing is that I could use these earlier (an earlier version of same
workbook saved previously under a different name has text boxes that I had
created).
What did I do inadvertently to cause this?
Any help would be appreciated.
Many thanks,
Stephen Powell

Further to my first message I find also that some other functionality has
become unavailable to me. For example, I cannot do Tools / Formula Auditing
/ Trace Precedents.
I'm baffled.
Stephen Powell

Several toolbars are wholly or partially "greyed out" (inactive). For
instance, Drawing toolbar allows me to use Fill Colour & Line Colour & Font
Colour but NOT to use Text Box, Connectors, Auto Shapes and others.
Odd thing is that I could use these earlier (an earlier version of same
workbook saved previously under a different name has text boxes that I had
created).
What did I do inadvertently to cause this?
Any help would be appreciated.
Many thanks,
Stephen Powell