Hi, I just encountered this issue. The issue appears to be route specific. In my case I was attempting to enter details for a EDDM -> LFSB flight and things hang up on a specific LFSB STAR entry. Here's the flow that reproduces 100% of the time for me ...
Locate the aircraft at any airport - in my case I'm using the A300-600RF PW w/ the IniBuilds provided FedEx livery starting from EDDM
Cold & dark
Turn on battery power
Connect to ground power
FMS
INIT (page A)
ROUTE: EDDM/LFSB - the from airport doesn't matter
COST INDEX: 50
CRZ FL: 240
FLT ID: FDX5225
F-PLN
Select LFSB -> STAR
APPRS: ILSY15
STAR: ARPU8K <-- THIS SEEMS TO BE THE KEY SPECIFIC STAR INPUT FOR THE ISSUE TO OCCUR
INSERT
INIT (page B)
BLOCK: Click LSK to auto-fill
ZFW: Click LSK to auto-fill
ZFWCG: 27.8
Click the TO/APPR button
RESULT: Will no longer be able to interact with the FMC or many other dials; particularly, on the lower displays. Tablet and overhead panel works fine. Aircraft itself is left in a wonky state as you can't start the APU (as one example)
