I've managed only 2 flights without WASM crashes in SU 14, and they were just local circuits around DEN and MIA. Since SU 15, none. Sim is updated to SU 15 and otherwise normal, no CTDs or weird behavior. Today I reinstalled the aircraft, and attempted to fly ORD-MIA KORD/09R N0461F350 DCT CMSKY DCT CARYN DCT CYBIL DCT PXV DCT HITMN DCT ACORI FROGZ4 KMIA/08R planned on Simbrief. I tried about a dozen times, each attempt ending in an aircraft freeze/WASM crash before I could leave the gate. I tried with the latest Navigraph database and default. I tried manually loading the aircraft, and importing from Simbrief. I tried manually building the OFP in the FMC and importing from Simbrief.The result is always the same. I found if I added the route first, and waited to do the init page 2 data, I could add the departure runway, arrival STAR and approach without a crash. EVERY time I entered the CG from the EFB, it would WASM crash. If I enter the init page 2 data first, EVERY time I added the arrival STAR and approach, it would WASM crash. I tried entering this data both during IRS alignment, and after. I tried during fueling, and after. I literally tried every possible sequence programming the FMC. All result in this crash. I'm at a loss, could SU 15 have borked the WASM code? No other aircraft I fly have had this issue, including the Flythemaddog MD-80 or TFDI MD-11. Any ideas?