I was doing some printing in Lightroom recently and was struggling. The prints were coming out really badly, and when looking for the quality controls for the Canon S900 I couldn’t find any of the normal settings. This is what it should look like, with options for the type of printing.

Canon S900 print dialog showing Quality and Media settings with Printing a composite document selected under Print Mode

But instead I was getting this, with a big crossed out option and an incompatibility over “architecture”.

Mac OS X Print dialog showing Canon S900 printer with a QualityMedia483 bundle error stating it cannot load due to incompatible architecture.

I was pretty confused why this wasn’t working and figured I needed to reinstall my drivers, but didn’t want to restart at that point so left it. I kept noodling this over and that word “architecture” was bugging me. Then it hit me!

I’ve posted before about how great Lightroom is in 64-bit mode. It dawned on me that I was running a “64-bit architecture” and the printer driver was probably only 32-bit. I checked the box for Lightroom to run in 32-bit mode and launched it again and the printer settings worked great! It sure would be nice if the error message just said “this doesn’t work in 64-bit mode”.

Lesson learned! Run Lightroom in 64-bit, unless you want to print, then restart in 32-bit. If anyone knows what printers have 64-bit driver support it would be great to have a list.