🚀 go-pugleaf

Why are you passing docRef to the Open method? All you need is the full file path. Until I saw this code, I didn't even realise that the Open method could take a second argument and looking at the documentation doesn't give much of a clue as to what the second argument is for. I presume it emulates the Open As command. In which case you would need a file type, not a document. Just drop it and this line should work.

Also, as an aside, your code for resizing looks a bit strange. Why are you passing null as the last parameter. This is an enumeration for the resample method with values from 1-6. You don't need to pass null for an optional parameter, just leave it out (same with the mode conversion). Not sure how you get that to compile. I get an error message saying null constant is no longer supported in VB.NET

Also putting values in for both width and height will distort the image (same as turning off constrain proportions) but maybe that is what you want.