That option was removed a while back, so the issue is likely that you have an out of date version of the Diagnostic Tool. Which is probably interfering with a platform update.
I don't have a Network Setup option. When I go into Networking it just gives the option to set a static IP, use DHCP, install WIFI Drivers and setup wireless.
Do what was mentioned above to reset it back to DHCP to be sure you have a proper DNS and it can resolve host names. Its in the Networking options, should be a button to "Switch to DHCP" or something of that nature. Its been a while since I have seen that screen.
Reset your hub network settings to use DHCP then go back and use that link again to update the diagnostic tool. After that run the platform update
*Also read the info from Bobby up above, he is Staff support. Sorry we are throwing a lot of things at you all at once!
@jtp10181 was on the mark - your platform version is very old. I'm still of the opinion that your hub isn't resolving names - do you have any router restrictions? Or have you setup a static IP for the hub without configuring DNS servers?
Why would I not have any issues with other devices if it was a DNS issue? It's talking outside my network or else I wouldn't get the notifications that there is a update available.
Thanks bobby, I've tried updating to 2.3.4.133 several times and keep getting the "error 500" message so i roll it back. Currently when trying to update the diagnostic tool I get "{"success":true,"message":"No Update for Diagnostic Tool Available."}" are you saying that if I update to 2.3.4.133 I should be able to update the diagnostic tool even if I get the "error 500" message, and not get the "{"success":true,"message":"No Update for Diagnostic Tool Available."}" error?
Do you have any vlan's setup? I'm with @aaiyar that this is likely a network issue. Lets start with the basics. Press the network reset button on the bottom of the hub for 7 seconds with a toothpick or paperclip. After the hub comes back up go to http://192.168.2.122/hub/cloud/updateDiagnosticTool again and wait. After it's done, reboot the hub and then try the platform update again.