With all due respect, what you just posted for QBDT in response to my comment is far more complicated and less likely to succeed than what I posted.

Folks, you don't need a converter (esp. given the sketchy nature of so many "free" tools out there).  All you need is the QFX file, and then open it with...never mind. I'm not going to rewrite it all.  All you need is Notepad (which comes with Windows computers).

Read my earlier comment. I lays out a perfect pathway to easily, quickly, and securely converting a QFX file to QBO format without a converter.  I've been doing it that way for more than a year, with nary a glitch.