Hello,
Thanks for reaching out.
wd is the short form of WebDriver
hub refers to Selenium Grid configuration where the two components are:
Selenium Grid Hub (is commonly termed as hub)
Selenium Grid Node (is commonly termed as node)
wd/hub is the part of the uri through which the node communicates with the hub
Hence to troubleshoot more I would suggest you to check Selenium Gird logs from application folder.
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