Created Unassigned: R engine not in a working state [130]

I am doing some predictions using R.NET - making data frames, running linear regression and then using predict method to obtain predictions. Everything run ok, until suddenly, I received (and received from then on):

```
RDotNet.EvaluationException: Unable to retrieve an R error message. Evaluating 'geterrmessage()' fails. The R engine is not in a working state.

```

What causes this, or how can I fix this - should I reinitialize the engine?

Thanks