Rather than trying to find an old version of adb, it’s easier to add quotes to the arguments to adb backup :
adb backup "-apk -shared -all -f C:\Users\NAME\backup.ab"
Rather than trying to find an old version of adb, it’s easier to add quotes to the arguments to adb backup :
adb backup "-apk -shared -all -f C:\Users\NAME\backup.ab"