I try to upgrade from Fedora 25 to Fedora 26 but when I use

Dnf --allowerasing -y system-upgrade download --releasever = 26

I get errors Error: Transaction check error: The /usr/lib/mono/gac/dbus-sharp/2.0.0.05675b0c3093115b5/dbus-sharp.dll file for the dbus-sharp-1 installation: 0.8.1-1.fc26.x8664 conflicts with the file Of the package dbus-sharp2-0.8.1-1.fc25.x8664 The /usr/lib/mono/gac/dbus-sharp/2.0.0.05675b0c3093115b5/dbus-sharp.dll.mdb file for the dbus-sharp-1 installation: 0.8.1-1.fc26.x8664 conflicts with The package file dbus-sharp2-0.8.1-1.fc25.x8664

The error is that the update conflicts with dbus-sharp2-0.8.1-1.fc25.x8664 to update it to dbus-sharp2-0.8.1-1.fc26.x8664 Any suggestion? Help!!