Thank you both for your replies.
@joanmarcel119 - yes, as I wrote in my OP, I went looking through all the VBA, did a ctrl-F search through every Object and Module looking for text string "NBBO", but it isn't anywhere in the VBA code. I'm guessing it's somehow renamed or something, but I don't have the coding abilities to decipher how it appears in the VBA to comment it out. And yes, I've written to IB to let them know about this...I'm surprised no one else has reported it to them because it's been broken for nearly a year!
@Richard L King - yes, the first thing I tried last night was just deleting Row 39, which didn't work. Tried deleting the NBBO columns on the Basic Orders page as you suggested, but still generates that error. Can you let me know what your 'further suggestion' might be to the code?
FYI I have periodically installed and test-driven the 'new' socket-based DDE API but for some reason it has never worked well for me. Performance is incredibly laggy and inconsistent, so I always find myself running back to the Legacy DDE, which is annoying because yes I'm told the socket-based DDE is supposed to be better / faster / more-functionality etc. And yet -- perhaps due to the way my workbooks are set up (I dunno?) -- Legacy DDE has always been the only one of the IB API's that has worked reliably for me. Going back 4+ years IB was saying that they were going to sunset the Legacy DDE, and I've written them periodically to ask whether that was still the plan (and to implore them not to do so)...and they've changed their tune a bit to "yeah, at one point we were going to phase it out, but for now we're keeping it but no promises for the future".
