When testing Safari 15 on Sauce you may receive an error like so:
Could not start a new session. Response code 500. Message: Infrastructure Error -- The Sauce VMs failed to start the browser or device.
While an Infrastructure Error might have many reasons in this browser it could be due to a specific error.
Check the test link created on the Sauce UI (you can check this by logging into your account and looking for the latest Safari test that is with status error)
On the POST session request you might see an error like so:
Capability 'acceptInsecureCerts' could not be honored.
Build info: version: '3.14.0', revision: 'aacccce0', time: '2018-08-02T20:13:22.693Z'
System info: host: 'itako3110.prod.miso', ip: '10.125.11.11', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.16', java.version: '13.0.1'
Driver info: driver.version: unknown
This is because acceptInsecureCerts is a capability not supported by Safari/safaridriver version 14.1 and above.
For more info on this see:
Easiest solution will be to remove the acceptInsecureCerts capability. If you need to test a site that has an insecure certificate, leveraging Sauce Connect Proxy will be a good solution.