More than a year ago i also got this problem
Simple Network Management Protocol & SNMP Trap Service are needed to access Lan Printers
i do not remember anymore what was the culprit.
but i know how i found it.
when Winreducer is compiling,You need to look what is compiling in the message windows.
it is one of the items processed before SNMP in Features was processed
Try this, do not select items in Presets below :
Presets Automatic Removing Process
Presets Automatic Removing Process (Optimize ISO Size)
Presets Use EXPERT Optimizations
Presets Protect Important Files
Presets Protect ModernUI Apps
Presets Protect MS Online Account
Presets Protect MS Office
Presets Protect Sysprep
Presets Protect VirtualBox
Presets Protect VMware Player and Workstation
Presets Protect Windows Activation GUI
Presets Protect Windows Features
Presets Protect Windows Media Center
Presets Protect Windows Media Player
Presets Protect Windows Search
Presets Protect Windows Update
and tell me if it works