New slight_18x275_Q2of0to1_omegaNeutralDecay_ab_hiAcc after abconv (crash investigation)

This file appears to crash geant4 with

-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : GeomField0003
      issued by : G4ChordFinder::FindNextChord()
Exceeded maximum number of trials= 75
Current sagita dist= nan
Max sagita dist= 0.25
Step sizes (actual and proposed): 
Last trial =         1e-69
Next trial =         1e-70
Proposed for chord = 2e-69

*** This is just a warning message. ***
-------- WWWW -------- G4Exception-END --------- WWWW -------


-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : GeomField0003
      issued by : G4RKIntegrationDriver::ComputeNewStepSize
Error is negative!
*** Fatal Exception *** core dump ***
G4Track (0x55b49948e298) - track ID = 4, parent ID = 0
 Particle type : proton - creator process : not available
 Kinetic energy : nan eV  - Momentum direction : (0,0,1)
 Step length : 0 fm  - total energy deposit : 0 eV 
 Pre-step point : (0,0,0) - Physical volume : AV_1435!BeamPipe_assembly_11#11!v_downstream_IP_vacuum_fill_4#4 (Vacuum)
 - defined by : not available
 Post-step point : (0,0,0) - Physical volume : AV_1435!BeamPipe_assembly_11#11!v_downstream_IP_vacuum_fill_4#4 (Vacuum)
 - defined by : not available
 *** Note: Step information might not be properly updated.

-------- EEEE -------- G4Exception-END --------- EEEE -------