Why does asset loading fail/load slowly?

This might not be the cause for this. But I was going into a game that was shared with me, and then studio seemed to freeze. So I alt f4'ed it and then after going into the game the loading seemed to take much longer. And then the assets didn't seem to load and then the output started spewing constant errors of failed loading. Below are some errors I got from a small game I have.

MeshContentProvider failed to process https://assetdelivery.roblox.com/v1/asset?id=********* because 'could not fetch'

Unable to load plugin icon.

Image "https://assetdelivery.roblox.com/v1/asset?id=********" failed to load in "Workspace.SpawnLocation.Decal.Texture": Request failed

Failed to load sound rbxassetid://**********: Unable to download sound data

Some assets actually managed to load but most important ones failed. This problem is really annoying as a game developer as I am unable to test things like welds as the meshes are invisible. And some decals are important too. Please help.