Situation: You check out/open a document or spreadsheet from SharePoint 2010 (Intranet) using the actual Office application (not in the browser). On attempting to save, you will either get a notification saying the document is already checked out by someone else or you just won’t see your changes. I’ve not seen this in Word, yet, but Excel 2016 is definitely being wonky.
Workaround: Save a copy of the document to your computer and make your changes. Check out the document in Intranet. Open the folder/library/docset in Windows Explorer. Drag your file from your PC to the SharePoint location in Explorer. Using the browser, check in your document. This will trigger workflows and everything else so you do not have to worry about that.
Obviously the workaround is a lot more steps than the normal check-out-and-open procedure for Excel documents. Editing the documents in the browser still seems to work, as well, but I haven't tested it as much. We have a lot of Excel documents with formulas and things which don't translate well to the web version.
Is there a CU that will fix this? We're not on the latest 2010 version at the moment.