I try to mount my secure webdav on my Ubuntu notebook, I've added the following to my fstab: https://[URL] /mnt/[folder] davfs user,auto,uid=wouter0100,file_mode=600,dir_mode=700 0 1 But when I run the command sudo mount -a I keep getting: /sbin/mount.davfs: Mounting failed. Server certificate verification failed: issuer is not trusted I've tried very much different things, but I couldn't get it working.. It's signed by Comodo and valid (when I load it in Chrome it's okay).