Try a different dns server on your pc

Either bad internet connection or you isp isnt allowing you to connect try using adifferent connection or switch to cloudflares dns or googles dns as it may help resolve the issue

If you read the FAQ which is here:
https://forum.plutonium.pw/topic/558/faq-common-issues-and-frequently-asked-questions-iw5
You would know the fix which is to do this:
Error: Failed to fetch info: Get "https://cdn.plutonium.pw/updater/prod.json": dial tcp: lookup cdn.plutonium.pw: no such host
Fix: Your DNS provider (likely your ISP) is filtering requests. Change your computers DNS servers to something that does not filter requests, such as 1.1.1.1.
I personally don't use cloudflares DNS server which is 1.1.1.1 but instead I use googles DNS which is 8.8.8.8

hey download this:
https://us4-dl.techpowerup.com/files/GvKAR8PjODxTR8MEr-X08A/1597267062/Visual-C-Runtimes-All-in-One-Aug-2020.zip and run the bat file as admin it will install all the vc redist versions which should fix the issue your having if you dont trust it then run a virus total scan on the files but this is the only I can think of to fix the issue as it does seem that the issue is your vc redist installation

Hey ya'll might wana get dotNetFramework 4.8 if you can if you continue to have this issue as the launcher wouldn't work untill I did have it installed don't know how it made it work but it did

Link to the official installer: https://dotnet.microsoft.com/download/dotnet-framework/net48