RS not loading has happened this week, which causes the game login trouble on PC. Currently Jagex has been aware of this RS Stuck on Loading Application Resources issue, and offered a solution for players to try.

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Statement on RS not loading issue from Jagex

From March 15th 2020, some players have faced RS Stuck on Loading Application Resources issue when trying to log into the game. Their client got stuck while “Loading Application Resources”, and didn't seem to be able to progress further.
According to Mod JD’s reply on Reddit, the develop team has been aware of this issue and is trying to replicate. They will keep players updated when they have a fix in place, hopefully sooner, rather than later.

Solution to RS Stuck on Loading Application Resources

According to Mod JD’s reply, players who suffer RS loading application resources issue could try deleting their cache (cache files inside C://ProgramData/Jagex/RuneScape). Notice that the only players who should be trying this method are those that have ran the installer recently, be that a re-install or a regular install. Any players experiencing slow loading will have their issue exacerbated by re-installing the game. In addition, this cache issue is Windows only.
Moreover, there is a possible solution shared by Reddit user u/caddph:
-Get a TunnelBear VPN trial;
-Set to the UK & connect;
-Launch RS client;
-After it finishes loading or you get to lobby, quit the VPN.

Hope RS Stuck on Loading Application Resources issue can be solved as soon as possible.

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