I have an odd issue when trying to play TPT while there is nothing to do while on a computer at school. I am able to connect to the powdertoy.co.uk website, download the game, open and play, however I cannot open saves/access anything online (all local). The school has the m86 webfilter, could it be why I could not connect to the server? If it were, why wouldnt it/they have blocked the main site?
So far the closest thing I had around the issue was a specific version (lost it when school ended last year) of TPT which was able to view online content (saves and such) while any other could not.
Has the server/name of the server in the code changed with the versions? I at one point as above had a version which would connect just fine while any other could not.
Your school might be whitelisting on an application level, it is very possible to block socket access for certain executables on both linux and windows (linux has some really weird method I don't remember anymore, I couldn't tell if it was filesystem based or some blacklist held somewhere, I think probably the latter).
My school doesnt have it blocked