Voltage drop across junctions in a bjt transistor
Where is my error?


There will always be a leakage current from collector to base and emitter (\$I_{CEO}\$). This might be in the region of 100 nA and, at that current, the base emitter junction appears to be forward biased as if that 100 nA were flowing through a diode. There might be about 0.2 volts dropped across base emitter in this scenario.