Excel utilities product warning
This warning mainly applies to Excel 2007 and 2010 users
Excel files must always be opened from within Excel or by direct file selection.
Do not attempt to open a new instance of Excel's Application when opening files, not only is it wasteful on memory but will cause issues with the add-in when preferences or information is being saved. If Excel has two or more applications open, with access to the same add-in file, and the save command is activated, Excel will attempt to save backup copies of the add-in to the documents folder as both xlam and xlsm files.
Excel 365 (2013-2019) is free of this issue, provided that you do not open an additional Excel as an administrator.