Error requesting server list from master server

[Evanito]

Specific case: Tried to use Team Fortress 2 tab (worked on clean install, changed some settings) error on the bottom bar says https://i.imgur.com/77zMgMo.png

Now all buttons do not work and popup the error message https://i.imgur.com/lGe1mlx.png (This error is when hitting the X button to close it. Had to force close using task manager.)

Found a solution by changing the TF2 master server to the alternate: hl2master.steampowered.com:27011

Then it at least did not lock up the program.

Expected behavior: Program recognizes a bad XML document and uses the alternate Master Server.

Thank you for your time and effort!