Error with task-based actions

I've created a workflow and added some actions such as logging and web service calls which are working.  However whenever I add an action that involves assigning a task, such as a flexi task or to-do task, the workflow proceeds normally up until the task action and then errors out with the nondescript message ‘An error has occurred in <workflow name>.’  Researching this I have not found anything online that points to a problem with setting up task-based actions.  I added SMTP to see if that somehow was a requirement but that did not fix it.  I’m wondering if since the error is a generic error that something low level, maybe with Nintex Worklfow creating tasks, is what is causing this, not sure.  I am able to add workflow tasks manually through the IDE.

Thanks.