Why are my onedrive documents opening in read-only mode after installing office 365 home edition?

I've never had that check box ticked, and have often had the problem of files "read only". I think the issue lies elsewhere, something related to where the file originated, perhaps. I find the issue occurs too irregularly for me to work out what might be causing it.

On another point, Microsoft have obviously been doing a great deal of work with OneDrive of late, speeding up the process of uploading and downloading from their servers. I am now allowing my PC to save to OneDrive rather than to my PC, and the delay in opening and saving a document has at last become quite acceptable. 

You may want to check your Office settings. You may notice an error telling you it couldn't sync thinking the error is coming from OneDrive when, really, it's coming from that Office Update Manager or whatever it's called.

Anyway, it's what worked on my wife's computer so it may not be everyone else's solution.

Something about, "I am the Word!" ... or my need for a scapegoat.

You think the Lord uses MS Word, too? Wow! ;-) That made me smile - thank you!

Agreed. No matter how many times I would uncheck the check box, when I would restart my machine, it would have rechecked itself. I don't seem to have the issue anymore, but it appears to have been divine intervention, rather than any "aha" moment on my part. Or I may have reinstalled the program; its been a while. I'm grateful for the many ideas on how to solve this, though.

I've never had that check box ticked, and have often had the problem of files "read only". I think the issue lies elsewhere, something related to where the file originated, perhaps. I find the issue occurs too irregularly for me to work out what might be causing it.

On another point, Microsoft have obviously been doing a great deal of work with OneDrive of late, speeding up the process of uploading and downloading from their servers. I am now allowing my PC to save to OneDrive rather than to my PC, and the delay in opening and saving a document has at last become quite acceptable.