What does “doesn’t recognize” really mean? - The files are not selectable by the Gerber viewer or the manufacturers upload tool (the files are all “greyed out”). Therefore, I upload them to the manufacturer in a zip file (which is recognized and an allowed file type by the manufacturer) and they are rejected. The files go to “audit” and 15 minutes later a message is returned, “File is not recognized. Please upload Gerber 274X file type”
How did they reject them, what feedback did you get? The message is, "“File is not recognized. Please upload Gerber 274X file type”
Which manufacturers? AllPCB and PCBWay
What do the viewers do with them? The files are not selectable - they are “greyed” by the app. However the drill files are selected and do display.
Which viewers? Cuprum for Mac as well as the Gerber viewer in Kicad.
Have you tried different projects? No.
Can you share an example file which is rejected? All the Gerber files are rejected. The reply doesn’t designate.