Using javascript to extract pages from PDF

Each month I get a large pdf file that I need to extract pages from and resave. The page numbers rarely change so this can had been working:

this.extractPages(0,1, "table1.pdf");

this.extractPages(2,15, "table2.pdf");

etc. for many more tables.

I recently "upgraded" to Adobe Acrobat Pro DC version 2021.005.20058

the code no longer works. I get an error message:

RaiseError: The file may be read-only, or another user may have it open. Please save the document with a different name or in a different folder. Doc.extractPages:1:Console undefined:Exec

There is no possible way for another user to have the file open - I just created it. I have searched on this error and seen many solutions, however none of them solve the problem.