It's not unusual to get this error with an offshore turbine. The message reads "Turbine has deflected..." for a bottom-fixed turbine or "...floated..." for a floating turbine.
Bladed sets a default wave-train extent based on a heuristic calculation, which does not always result in a large enough value. You can set your own value for the wave-train extent using the "Special Data" window in Project Info. For an introduction to this functionality, refer to the document "Bladed Project Info options" under User Guides here. The text to enter is as follows (taken from the Project Info document):
MSTART EXTRA
WaveExtent 150.0 ** (example, 150 metres) Extent of wave train in metres (upstream and downstream)
MEND
(Steps: Go to "File" -> "Project Info")
The custom wave train will extend by at least this distance, both upstream and downstream. This value will only be applied, in either direction, if its absolute size in that direction is greater than the default wave train extent calculated by DTBladed.
If this doesn't solve the problem, it's probable that the simulation is going unstable. This may be fixed by adjusting integrator settings for instance.