DC voltmeter yields a value with 21% error
When a string of voltages does not add up to what you expect, you check each individual part to understand why.

Vf for small Silicon diodes and Vbe near 1mA is around 0.65V.

Note that just by rearranging the same loop it may be easier to understand the  R1 controlled loop current. 

If we assume they are ideal 3V batteries and a real diode, I would expect smilar value of what you show, except the opposite polarity.







simulate this circuit &ndash; Schematic created using CircuitLab

Note your meter polarity is reversed.