Question: mailto: appears in excel
I use excel for mac 2008, and whenever I tab from other open programs, a mailto: and my gmail address appear in a grey/brown box on the sheet. It can't be clicked on or deleted and just sits there blocking out a small section of the sheet. If I tab to other programs, it disappears, so only shows in excel. If I tab to other worksheets it stays on the screen, so shows on every worksheet, but not any other programs.
Any ideas how to get rid of it ?
MacBook Air, macOS High Sierra (10.13.3)