Below is a post from me tonight on Microsoft Community.

My first reply asked if I first ran the Offline Quick Repair. (of course I did otherwise why would I spend all the time on the Online Repair/Reinstall Office.
Based on reading many of the MS forum members comments on multiple topics I wonder at times whether some people posting answers" actually read the questions submitted.
Some contributors do give very valid suggestions so it is worthwhile to remain a member.

Having moaned above has any PC World Forum member experienced my problem below?.

Office 365 Home Fails again
I am Win 10 64 Bit Version 1909 and take all updates routinely. I have used Office 365 Home for several years initially on Windows 7 then with Windows 10.
Last night all my Office 365 programmes worked normally.
This morning none would open and I got the usual types of error message.
Error 0o000012f appeared on all.
Then I would get error messages such as cannot find file C:\Program files (x86) Microsoft Office\root\Office16\ EXCEL.EXE -WinWord.exe , OUTLOOK.EXE etc yet all those files showed up in those places.
When I clicked on such EXE file I got various Error messages such as " not recognised by Win 10" (which is nonsense) or File may be corrupted.
I fail to see how such files could all be corrupted when the PC was turned off overnight.
In desperation I took the 2 latest Optional Updates this afternoon for Win 10 64 bit Version 1909 in the hope maybe they would fix matters -no luck.
I had to resort once again to Online Reinstall (through Apps and Features) to get Office 365 working again.
A lot of lost non-productive and stressful time.
Has anyone else experienced this 0o000012f error in the last few days?
NOTE Office 365 Home is not listed in the Tab options below -merely Office 365 Admins which is aimed at workplaces with multiple pcs , That is why I was forced to select More Office apps