Forum Discussion
Bug - Deleting custom number format used in conditional format corrupts Excel file and cannot save
I think I have found a bug in Excel that has existed for some time and still exists in current version of Excel 2019. This can be easily reproduced in all recent versions off Excel, across versions ...
Your best bet is to replicate the issue, write out everything you wrote in your message above into the spreadsheet, making sure all text and the screenshots are visible on the same window (no scrolling required) and then click File, Feedback, "I don't like something" and fill out the form, checking the screenshot box..