Segmentation fault on GPU for almost all input files

After fixing the bug #14 (closed) it seems to runs fine on CPU. However, when running any test file on Gwendolin, the program has a segmentation fault after initializing the beam.

Example: /opalx/input-files/test-0001.in

The last few lines in the output look like this:

OPAL-X> * ************* B E A M ************************************************************ 
OPAL-X> * BEAM        BEAM1
OPAL-X> * PARTICLE    ELECTRON
OPAL-X> * REST MASS   0.000510999 [GeV]
OPAL-X> * CHARGE      -e * 1 
OPAL-X> * MOMENTUM    1.00051e+09 [eV/c]
OPAL-X> * MOMENTUM    1.00051 [GeV/c]
OPAL-X> * CURRENT     1.3e+06 [A]
OPAL-X> * FREQUENCY   1.3e+09 [MHz]
OPAL-X> * NPART       10
OPAL-X> * ********************************************************************************** 
OPAL-X> 

...then it just stops. The error file only shows the following:

[merlin-g-100:127513:0:127513] Caught signal 11 (Segmentation fault: address not mapped to object at address (nil))
==== backtrace (tid: 127513) ====
 0 0x0000000000012cf0 __funlockfile()  :0
=================================
srun: error: merlin-g-100: task 0: Segmentation fault (core dumped)

The error does not appear for test-0000.in. This test does not call any "RUN ...", so the error might be somewhere in the Track[...].cpp files.