If when running a worksheet or evaluating a specific line in the worksheet, you always get a popup, (or if a command from the context panel is evaluating that you don't want anymore),the first thing you should do is go to View and select markers.
This will reveal this bar on the left of your document.
The red lines in this bar show auto execute and document markers. These markers will tell you if any formatting such as numeric formatting has been applied as well.
If you right click the line and select Document block > Show command
You'll be able to see the command that's actually evaluating
Highlighting the command and hitting delete will remove it from your worksheet .
Then you can run the worksheet as normal and the popup won't appear.
The video attached at the bottom of this FAQ will show you the steps.
Some relevant help pages are: