This issue has resolved itself after I restarted my Ubuntu 16.04 VM and started all three tyk services (tyk-gateway, tyk-pump, tyk-dashboard). I have since gone on to create additional APIs, add users, create keys, etc. without encountering any additional issues. If this particular issue occurs again, I will share my tyk gateway logs. The logs I currently have would probably create confusion, since I tried so many different things yesterday. Anyway, I am thrilled to continue playing with this impressive API Gateway!