@Maybelle_S
RE: This error usually occurs when the file association of the IIF file is changed to other applications than MS Excel.
Well... the QuickBooks installer sets up IIF files to be associated with QuickBooks, not Excel. It has always done this and it's always been sort of dumb as then when you double-click an IIF file then you get a QB warning that you can't open IIF files in this way.
This means that, basically, the button in QuickBooks doesn't work for anyone unless they actually change the file association. And, based on this thread not even that works sometimes.
I've no idea why Intuit implemented things this way. It is easy enough to launch Excel and tell it to open the file instead of just launching the file and hoping the computer is set up to open it in Excel.
If you're one of the almost-everyone who can't open the error files from within QB, you can open them from within Excel by starting to open a file and then navigating to the folder where you put the original IIF file and then picking "All Files (*.*)" in the file open dialog. Then you'll see both your IIF file and the one with the ~ "_65465454" extension added to the file name.
Also, see BRC QuickBooks 2019+ IIF Import Changes and Recommendations and avoid all this by importing using the alternate method (which Intuit has tried to make sound scary, but works a whole lot better.)
