i am unable to get the background settings in microsoft teams

Nice solution, but what if I don't have working machine to copy the files from?

Are you able to post the correct file structure so that I can try manually recreating the folders, please?

I think it should be in here:

C:\Users<Username>\AppData\Roaming\Microsoft\Teams and then I think you need a folder called Backrounds within which there is one called Upload, but that's purely from memory as mine seem to have disappeared completely following my uninstall and re-install. Mine currently looks like this:

Many thanks for your help and advice,

Caspar

is this possible for mac too?

I got it to work on my problematic PC.

I did this - 

1. Exit Teams and Outlook
2. Delete the %appdata%\Microsoft\Teams folder
3. Go to a PC that does have backgrounds working and zip the %appdata%\Microsoft\Teams folder
4. Copy it to the problematic PC and extract to %appdata%\Microsoft\
5. Start Teams
6. Enjoy your backgrounds!

My Teams worked fine with background choices on my laptop on the morning on 12th May 2020, but by the evening it had stopped working. When choosing Backgrounds the right hand panel has that title but is now completely empty and there are no choices available. I have tried uninstalling and re-installing Teams but it has made no difference. The above hyperlink from @MGREYES took me to Microsoft Office support and they politely told me that they can do nothing about Teams and that I need to contact Professional Support

I believe you would have to contact their Support Team directly to hear back from them. https://support.office.com/en-us/home/contact?contactUsExperienceEntryPointAssetId=S.HP.teams