Windows 7 drivers have been installed on Windows 10 in compatibility mode. Works fine in OpenOffice, Write and other applications. ONLY LibreOffice refuses to print. Have tried installing “master” copies of LibreOffice, same result. The problem is in LibreOffice alone. The printer works perfectly under Windows 10 and any other software. Would like to use LibreOffice, but an office quite without a printer is useless.
Try restarting in Safe Mode via “Help” > “Restart in Safe Mode…” and see if hat helps. Report back with your findings.
Is there another similarly named printer in the Printer ifeld (Ctrl+P > General tab) that you could try? Sometimes a second printer driver is created by Windows but only one works.
Apparently Dell Open Print Driver works for 3100cn , see rsinj comment on page