PROBLEM SOLVED - for me anyway! I got a response from Brother about double-sided printing. They sent me a link to update the printer drivers. Then I had to delete the old printer and add the new Brother printer. I am happy to say that has resolved my problem and I can now print multiple pages single-sided from Adobe Reader, Adobe PRO and Preview - just like I could before. "Please click on the link below to update your drivers for Mac 10.13: http://support.brother.com/g/b/downloadend.aspx?c=gb&lang=en&prod=hl3170cdw_all&os=10045&dlid=dlf102912_000&flang=4&type3=10062 Once this is installed, please follow the steps below to ensure you are running the correct Drivers: Click on the Apple icon in the top right hand corner> System Preferences> Printers and Scanners Click the + icon on the bottom left hand side > Select the Brother printer (HL3170CDW) Change the name of the Brother Printer to "New Brother Printer" Use the drop down box called "Use" and select the (HL3170CDW) CUPS printer driver Select Add > Continue > You will be taken back to the main Printers and Scanners page. Ensure "New Brother Printer" is set as the default printer. Remove all other copies of your Brother Printer, leaving New Brother Printer as the only one. Once this is done, please check the print dialogue box and try printing again." Just to clarify, I am using a 2017 iMac running High Sierra and using a Brother HL-3170CDW printer. Good luck to everyone else having the same problem. Best regards Janet ... View more

Hi I'm going to try using Mac preview to print in future, although I really like using Adobe Reader for PDF's. We do have Adobe PRO and I just tried printing a 3 page PDF from that on my Brother printer and that printed single sided, so for me I could have a solution. I just don't understand why developers mess around with the areas of the app's that work perfectly when they do updates!?!!? It's so frustrating! Best regards Janet ... View more

Hi I've just emailed Brother about the problem, so I expect I will get the same response you did. Fortunately we still have our old 2011 iMac and can use that to print single sided onto pre-printed forms which cost a lot of money. I've wasted two of these in the past 2 weeks costing us over £100! Thanks Adobe!!!! Best regards Janet ... View more

Hi My "media and quality" setting was set to "double-sided" so I unchecked it. However it still prints double-sided. Thanks for the info though. I'll keep looking for a solution. This has only happened in the past two weeks when I got a new iMac running High Sierra, so maybe it is an Apple problem? Best regards Janet ... View more