TCL error: invalid command name "1" on GTM

This looks like a bug in the GTM iRule parser. Here's a simple way to reproduce it:

when DNS_REQUEST {
    if { 1 == 1 } {
    }
}

Here's a workaround:

when DNS_REQUEST {
    if { not [active_members Global-webservices.landsbanki.is_A10_pool] and not [active_members Global-webservices.landsbanki.is_RB_pool] } {
        drop
    }
    elseif { [IP::addr [IP::remote_addr] equals 89.104.145.0/24] } {
        if { [active_members Global-webservices.landsbanki.is_A10_pool] } {
            pool Global-webservices.landsbanki.is_A10_pool
        }
        else {
            pool Global-webservices.landsbanki.is_RB_pool
        } 
        return
    }
    elseif { [IP::addr [IP::remote_addr] equals 89.104.148.0/24] } {
        if { [active_members Global-webservices.landsbanki.is_RB_pool] } {
            pool Global-webservices.landsbanki.is_RB_pool
        }
        else {
            pool Global-webservices.landsbanki.is_A10_pool
        } 
        return
    }
    elseif { not ([IP::addr [IP::remote_addr] equals 172.27.0.0/16]  or [IP::addr [IP::remote_addr] equals 89.104.128.0/19]) } {
        drop
    }
}

You could open a case with F5 Support to have them look into the issue. It might be fixed already in the current v11 beta as I believe there has been a lot of work done on GTM iRules in the upcoming version.

Aaron