Hybrid initialization is solving an Euler solution for your problem to help orient the velocity field better than a fixed value everywhere in the flow field. There are several reasons why you could encounter the error. Look at the flow field that is produced simply by the hybrid initialization (meaning, do not iterate any further). Does it make sense? Sometimes there will be a false boundary condition or other problem that is apparent due to this warning.

If everything looks alright, then you can continue. Keep in mind, this is only an initial "guess". We will iterate towards our final solution. The final solution is independent of the initial guess (well, it should be in most cases).