One occasional error is not really anything to worry about. Can be due to lots of things.

Only start worrying if it happens often

Nothing so dramatic. The Seti science application keeps track of what's happening to the data it is calculating. If results stray out of boundaries, the task will be aborted, usually with a compute error (is what it's called in BOINC). Your task erred with computation error -194 (I saw earlier today) which can mean that the project aborted the task. I don't say that happened, but it's a possibility. Else it's just a myriad of options and oddities that can happen by which a task doesn't finish correctly. As Bernie said, don't sweat it, if it happens once or twice in a day. Only worry about it when it happens all the time, as then either there's something wrong with the batch of tasks, or with your computer. Now neither of those cases is true.

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