Cannot download x86_64/insync-1.3.17.36167-fc26.x86_64.rpm: All mirrors were tried; Last error: Status code: 404 for http://yum.insynchq.com/fedora/26/x86_64/insync-1.3.17.36167-fc26.x86_64.rpm
@Cosme_Correa: The Fedora 26 build has recently been removed because it is crashing for some users. For now the build for Fedora 25 is being served. Please update your repository information by running sudo dnf clean expire-cache then sudo dnf makecache.