Same issue, presents the same error upon start of any mission, any aircraft. Also when trying to make a new mission - it error occurs once I have selected which map I want to use and try to start mission editing.
Tried pre and post update of NVIDIA drivers plus with and without Rift CV1 running.
Deletion of specified files (FXO etc), cleanup and repair completed.
Also tried deleting metashaders followed by repair (hence "2018-04-25 20:35:32.520 ERROR RENDERER: Failed to build metashader:........")
240GB SSD nmve (OS only)
CV1 Rift dcs.txt