Description
After version 2021a, in order to reduce the file size, Webots set resource files such as textures and sounds up for network download by github. However, for well-known reasons, github is very inaccessible in China, so there will be errors like:
ERROR: Error downloading EXTERNPROTO 'StraightStairs': Cannot download 'https://raw.githubusercontent.com/cyberbotics/webots/R2022b/projects/objects/stairs/protos/StraightStairs.proto', error code: 1: Connection refused
ERROR: Error downloading EXTERNPROTO 'Spot': Cannot download 'https://raw.githubusercontent.com/cyberbotics/webots/R2022b/projects/robots/boston_dynamics/spot/protos/Spot.proto', error code: 1: Connection refused
ERROR: Error downloading EXTERNPROTO 'Roughcast': Cannot download 'https://raw.githubusercontent.com/cyberbotics/webots/R2022b/projects/appearances/protos/Roughcast.proto', error code: 1: Connection refused
ERROR: Error downloading EXTERNPROTO 'ThreadMetalPlate': Cannot download 'https://raw.githubusercontent.com/cyberbotics/webots/R2022b/projects/appearances/protos/ThreadMetalPlate.proto', error code: 1: Connection refused
which means you can't download resource files from github.
Solution
We can change the network preferences in Webots.
Click preferences->network, in the proxy column, check SOCKS v5, fill in 127.0.0.1 for Hostname and 7890 for Port.
Attention:First of all your own computer should have a proxy, and the port is related to your own settings.