Unable to access data in numerous Windows shares today after the (KB4480970) update.
When trying to access shares the error "The handle is invalid" is displayed.
Microsoft has suggested various work-arounds but the only fix we have discovered is to completely remove the KB4480970 update.
Update: Microsoft have now released an update to resolve this issue which can be download from here
Microsoft have also explained this only affected users who in the local administrators group which is often the case in a Windows Workgroup environment.