Diodes shall never be put in parallel.
The false theory, is that the current will be spread accros the two diodes.
In fact what will happen is that the diode whith the lesser forward voltage with let pass more current. Provoking a rise in temperature, this rise in temperature cause the forward voltage to decrease even more. Due to the negative thermal coefficient of diode junctions.
This is explained in the following document : AN4381 Application note