XC60 D5 – “Motor maintenance required”

Hello municipality, now it has also caught me, yesterday suddenly the yellow warning “motor maintenance required”. To the background, my five-cylinder from Mj. 17 (the old) has completed in the last years each 12-15 Tkm in the year, short but also long distance, largely trouble-free. So far no performance losses noticeable, no emergency run report. Last service 7 months ago, of course at the FVH. I asked for the oil level, which showed itself just in the red bordered field right, i.e. it could have “mistaked” “some” diesel in the engine oil. What else could come into question?? My friend can only read out the error memory on Tuesday, but complained immediately with overload and booked out for at least 2-3 weeks. In one week however, I want to reach my holiday domicile in Croatia. Who has similar experiences and can give tips ??