Reverse biased diode
For ideal components, the circuit is described by ill defined mathematical equations. The ideal diode when reverse biased will present infinite resistance. The ideal voltmeter also has infinite resistance. So the voltage division formula will be
\$V_{\text{voltmeter}} = \frac{\infty}{\infty + \infty}\$.
For realistic components, the volt meter would read some value which is highly dependent on the resistance presented by the two components.
Load line for reversed biased diode not in break down region

If the volt meter shows 2.8V, your circuit is probably situated at the intersection of the two black lines. If there is a small change in the multimeter resistance, the voltage across the meter change. Blue line shows a multimeter with lower resistance. If the diode has higher reverse leakage current, that can also change the reading. Red line shows such a case.