So I am having an issue where I am trying to copy a graph from an excel file to a powerpoint file and every time I try, powerpoint freezes and then I get a message saying that the excel file is open in another application when it is in fact not. I've tried many things and I was just using it yesterday without issue.
What have you done trying to solve the issue? It would be a lot easier to troubleshoot knowing. But I assume you have repaired Office (Quick Repair), disabled Add-ins, checked the file properties in Windows Explorer, created a new Excel file and moved the content, confirming there is no sync problem with OneDrive etc.?