The conversion of the project was successful.

The new directory structure is as follows:

N:/Projects/MDPS/simulation
    mdps_sim.opj
    mdps_sim.dsn
    mdps_sim.dbk
N:/Projects/MDPS/simulation/mdps_sim-PSpiceFiles
N:/Projects/MDPS/simulation/mdps_sim-PSpiceFiles/SCHEMATIC1
    SCHEMATIC1.net
    bias.sim
    SCHEMATIC1.als
N:/Projects/MDPS/simulation/mdps_sim-PSpiceFiles/SCHEMATIC1/bias
    bias.out
    bias.out.1
    bias.mrk
    bias.cir