Ansible Error: An exception occurred during task execution

Problem solved! At least for us. In short, the module in our playbook needs to be executed on the Big-IP itself which uses Python 2.7 and causes the "split()" error. In most cases this can be resolved with "connection: local" or "delegate_to: localhost", as it is with all the F5 Ansible modules. In our case the solution was a bit different, you can check the GitHub issue for explanation.