If you were in a race viewer at the time this occurred, you probably didn't notice anything. Race viewers, race simulations and race results were unaffected. Only when loading content from igpmanager.com such as initializing the app or going to igpmanager.com would some people have encountered the problem.
Thanks for your patience. If you need assistance with any situations that occurred as a result of this interruption please post here.
UPDATE 2018-01-04
Mystery solved. Our host brought a planned maintenance forward with almost no forewarning and rebooted our servers without us knowing in order to patch the recently revealed Intel Chip security flaw. This unanticipated action on their part caused some services to fall over during the reboot, and this is why the site was temporarily inaccessible. For those of you concerned that the fault was somehow a reflection on the service we provide, I hope this helps to put those concerns to rest. The situation was unexpected and not our doing, but ultimately was to ensure the security of the system.
To quote their email to us directly:
An industry-wide, hardware-based security vulnerability was disclosed today. Keeping customers secure is always our top priority and we are taking active steps to ensure that no Azure customer is exposed to these vulnerabilities.
The majority of Azure infrastructure has already been updated to address this vulnerability. Some aspects of Azure are still being updated and require a reboot for the security update to take effect.
You previously received a notification about Azure planned maintenance. With the public disclosure of the security vulnerability today, we have accelerated the planned maintenance timing and began automatically rebooting the remaining impacted servers starting at PST on January 3, 2018.
The majority of Azure infrastructure has already been updated to address this vulnerability. Some aspects of Azure are still being updated and require a reboot for the security update to take effect.
You previously received a notification about Azure planned maintenance. With the public disclosure of the security vulnerability today, we have accelerated the planned maintenance timing and began automatically rebooting the remaining impacted servers starting at PST on January 3, 2018.