In A103: REBOL system error #9910
I should mention that a new un-documented assertion was added to the wake-up function in A103.
The 9910 error occurs if wake-up is called on a PORT type that is not at least the size of a standard port object. You can MAKE larger ports, but not smaller ones, because wake-up needs to be able to reference the port-actor and/or port-awake fields.
If you're now seeing this error in your R3 scripts, then we may have some kind of port problem. Please provide a short script in CureCode and we'll investigate it.
Note that this error is valid if you've created an invalid port somehow. In theory, that should never happen, but if we find it does, then we'll document this error, and we can also make it non-fatal.