We just checked the system and everything appears to be normal. Please check if you can log on to DriveHQ.com website. If so, you should be able to log on.
DriveHQ WebDAV Drive Mapping service does not limit number of concurrent connections. You can have multiple users, each having multiple computers connected to the cloud drive.
The problem you reported appears to be a network problem. (e.g. your router, firewall, ISP or anti-virus software blocked connection to DriveHQ.com website, or your DNS server is having a problem). If you cannot solve the problem, please open the Drive Mapping Tool software, click Advanced, then click Event Log -> "Send Event Logs to Support". We can then check the problem further. Please also tell us if the problem only affects new computers? What about the cloud drives that you have aleady mapped?