The error appears on K2 Runtime Sites: "The anonymous token supplied is invalid."
It will be possible to access the K2 Runtime anonymous site, but it will fail to load the needed runtime page:
The anonymous token supplied is invalid
You can try adding the following setting in the AppSettings section of the relevant Designer/Runtime web.config file:
<add key="Forms.AnonymousAuthorizationModule.TokenServerVariables" value="None" />
Designer/Runtime web.config files can be found in the following locations:
C:\Program Files (x86)\K2 blackpearl\K2 smartforms Designer\Web.config
C:\Program Files (x86)\K2 blackpearl\K2 smartforms Runtime\Web.config.
To resolve this issue, please log a K2 Support Ticket on the K2 Customer Portal for assistance as this needs to be configured on the K2 Cloud Instance.