I have the exact same problem and am currently talking to Formlabs support to resolve this problem.
I am getting the exact same screen as the one depicted in the screenshot above and I will detail below.
Here is my setup:
I have two Form printers,
one Form 3 and one Form3B.
Both printers are on the same LAN network,
Both have the latest Firmware update (as of 15/MAR/2021)
Here are the things I have tried
After parts would not print on the Form3 I printed the same model on Form3B
RESULT: Form 3B the part loaded normally and printed just fine
Tried Printing another part to make sure that my file was not corrupted
RESULT: Same window as before, stuck at 40%, just as before.
Manually uploaded the newest Firmware fill and installed it again on Form3
RESULT: See 2
Did a factory reset on the printer and tried to print a different file
The only difference between the two printers is that the one that still works was not on the same network for the previous 3 weeks.
I will let you guys know what the solution will be that Formlabs will come up with…
BTW: Big shout out to the Formlab support team.