Many thanks to you guys for your help. I knew about the English (US) Language Pack and had it installed for a couple of weeks but it did not cure the problem. Then when I saw your screen shot I noticed that you’d got more icons showing against both of your Language Packs and so, I attempted the get the same. Don’t know why but it nows works and once again I can open Options>General.
I’m sure that I’ve been running this sim for many months without that English (US) pack running!
Anyway, thanks for your responses. Best wishes.