keep getting "iPad cannot be synched. internal device error"

so I've been getting the above error since the latest round of updates for iTunes, security updates, etc... however I'm still on el captain 10.11.6 as it still meets the requirements.... can't figure out why i can't complete a sync. does this

/Applications/iTunes.app/: a sealed resource is missing or invalid

file added: /Applications/iTunes.app/Contents/Resources/iTunes.help/Contents/Resources/en.l proj/Art/dmg.json

file added: /Applications/iTunes.app/Contents/Resources/iTunes.help/Contents/

mean anything to anyone. any help? Tks!

Also getting this pop up when i start iTunes,

Do you want the application “iTunes.app” to accept incoming network connections?