With our planned move to automated VM-based testing, we’ve been preparing a proof-of-concept VM. Its sole function is to act as a sandbox for running Selenium tests, controlled from another machine. However, those tests seemed to be timing out when getting a DOM element by ID.
The problem turned out to be that the VM hadn’t had our client installer run on it, and the .NET ActiveX controls weren’t loading due to insufficient code permissions. IE was repeatedly trying to load them. So now we know.