There is not enough information in the screenshots to know what is wrong, you can have a look at Having problems with UrBackup? Please read before posting for ideas about collecting problem reporting information.
I have encountered a similar error message when urbackup was connecting using IPv6. You can confirm how the server is connecting by looking at the IP address of the client on the server summary screen. This column is not shown by default and you need to use the show/hide button and add the IP column.