Infrastructure changes to the S3 proxy will be introduced on March 19th, 2020. Site Administrators for clients impacted by this change have already been notified by a banner.
If your studio has network restrictions, please check that the IP addresses 188.8.131.52 and 184.108.40.206 are whitelisted. The media access URL will change from https://proxy-sg-media-usor-01.shotgunstudio.com to https://s3-proxy.shotgunstudio.com.
You can check your configuration by accessing https://s3-proxy.shotgunstudio.com/ and should be expecting a page with the following: