It is stated in the patch notes for 6.7.5 that this was corrected.
In version 6.7.5 (06.08.18) :
!!! A license synchronization is required before the update of PVsyst !!!
String inverters: add. info, and warning when choosing "Use Multi-MPPT"
Help about bi-facial: add a page explaining the results in detail
Projects involving Mixed orientation: errors in simulation
(namely on IAM and near shading losses)
CSV hourly files: error in the version 6.74: many values were null !
Ageing tool: always reverts to 10 years when entering the dialog.
Solar parameters tool (plots): some insignificant errors.
Maxim optimizers: little error in simulation => Ohmic loss = 0.