hi ,i met the same question and did't know how to find the source of the problem.
when i tried to backannotation ,it always occured the following errors :
#549 ERROR(SPCODD-549): No physical part found for COMP_DEVICE_TYPE=EP2C70F896_4_BGA896_EP2C70F896, regenerate the netlist to sync with Allegro board.
ERROR(SPCODD-516): Line Number: 13
#1 Error [ALG0037] Unable to read physical netlist data.
#2 Aborting Swap file creation... Please correct the above errors and retry.