VBA to Open All Workbooks in Automatic Calculate

Hello, I am hoping someone can help me here, as I have been beating my head against a wall trying to make this work. Everything I have tried has failed, and usually I can figure these issues out.
We sometimes have people send us files with formulas set to manual calculation. The recipients want them to always open and re-set to automatic calculation. I have tried class modules, using this workbook, calling the operation separately, and application events. Everything I have seen has noted this to be the code, which should be put into the 'ThisWorkbook' area of the Personal folder:

Private Sub Workbook_Open()
Application.Calculation = xlAutomatic
End Sub

Seems simple enough, right? Well, every time I try to run this at the application level, I get the runttime error 1004. Which seems to indicate that the command will not run unless you have a workbook already open. But I keep seeing this work for other people, at least online. I tried to run it with the command workbook_afteropen() as well. I am just at a loss.
I tried to run it as a module with auto-run, but when I tried that, excel kept saying it was an ambiguous name. I just do not understand why this will not work. I have Office2016. Did something change in 2016 where this will not work anymore?

Really hoping someone can give me some guidance. It should not be this difficult to set excel to auto-calculate as a default, but if someone sends you a manual calc file, it sets that way. Then everything else you open after that opens in manual, which just becomes a nightmare if you were unaware. I have all macros enabled, I run macros all the time. Just this one is not working with me.

Thanks for any assistance!

Edit: so I just found out that cross-posting is an issue, sorry, had no idea! I have this in two other forums. Had no idea any of you all were connected, I was just out looking for an answer and figured I would post in as many places as I could to get as many answers as I could. I even chose the exact same name, so it should be easy to find!

Here are the links:
https://www.mrexcel.com/forum/excel-...ml#post4865188

http://www.ozgrid.com/forum/showthread.php?t=204780