PDF Editor Is Unable to Handle Simple Job - Error Messages

I was having trouble with my computer not baing able to handle editing architect's drawings in the online pdf editor SO I BOUGHT A NEW COMPUTER!! I now have an i7 processor and a RTX 4060 graphics card. Plenty powerful enough. And guess what? I still can't edit pdf documets online because I get two error messages.

When I first load the drawing into the editor I get:

'Please wait while edit is being prepared' - blue pop up at bottom of page

And then:

'Page is unresponsive' - popup at top of the page

It's like the computer is still struggling to process the document. I then have no other option but to close the page having failed to edit any drawing which is what I'm paid to do by my work. Anyone have any ideas as to how I can access the online pdf editor with my powerful new computer so I can do my work?!