I have a spreadsheet saved to my portion of OneDrive for business which can be accessed using a web browser/Excel for Web. For about a year it worked perfectly allowing multiple people to edit at the same time. Then suddenly last month we started getting this error intermittently when trying to update cells.
Sometimes the error appears for one user but another can do the exact same thing seconds later without trouble.
I've tried cutting down the quantity of data and saving as a new file name and link, but neither solved the issue.
A web search found a similar-sounding issue and the suggested fix was to restart the SharePoint server. Unfortunately I believe our OneDrive is hosted in the cloud, so that's not possible: