[2019] My or server problem?

Development aware of this issue, but it can be resolved in most cases by simply restarting your PC, clearing your Steam download cache or changing your Steam region as mentioned by Rizz.

Unfortunately, the issue may arise again meaning you'll need to repeat the above which I appreciate is less than ideal.

I apologise for not being able to shed more light on the issue, but I simply don't have the details at the moment.