Error while fragmenting

Dear developers of the Flux Simulator

I am using the Flux Simulator to generate 80M paired-end reads, but I keep getting the following error

[WARN] merging exon (-145738769,-145738864) with exon (-145738601,-145738767) in transcript NM_004260 because intervening intron has 4 or less nt.}}
*[WARN] merging exon (-104464279,-104464281) with exon (-104463611,-104464277) in transcript NM_031274 because intervening intron has 4 or less nt.
[WARN] merging exon (-104464283,-104464442) with exon (-104463611,-104464281) in transcript NM_031274 because intervening intron has 4 or less nt.
OK (00:00:22)
[INFO] Initializing PWM cache
[INFO] Done
[LIBRARY] Reverse Transcription
[LIBRARY] Configuration
Mode: RH
PWM: default
RT MIN: 500
RT MAX: 5500

Processing Fragments ********** FAILED
[ERROR] Error while fragmenting : fromIndex(870) > toIndex(869)
java.lang.IllegalArgumentException: fromIndex(870) > toIndex(869)
at java.util.Arrays.rangeCheck(Arrays.java:1306)
at java.util.Arrays.binarySearch(Arrays.java:1780)
at barna.flux.simulator.fragmentation.FragmentReverseTranscription.process(FragmentReverseTranscription.java:261)
at barna.flux.simulator.fragmentation.Fragmenter.process(Fragmenter.java:591)
at barna.flux.simulator.fragmentation.Fragmenter.call(Fragmenter.java:217)
at barna.flux.simulator.SimulationPipeline.call(SimulationPipeline.java:428)
at barna.flux.simulator.SimulationPipeline.call(SimulationPipeline.java:53)
at barna.commons.launcher.Flux.main(Flux.java:196)

[ERROR] Fragmentation file /demeter-internal/jasi/projects/transcriptome_assembly/benchmarking_flux/flux_simulation.lib not found. Make sure fragmentation was done !

[DEBUG]

[DEBUG] Error while executing class barna.flux.simulator.SimulationPipeline : Fragmentation file /demeter-internal/jasi/projects/transcriptome_assembly/benchmarking_flux/flux_simulation.lib not found. Make sure fragmentation was done !
java.lang.RuntimeException: Fragmentation file /demeter-internal/jasi/projects/transcriptome_assembly/benchmarking_flux/flux_simulation.lib not found. Make sure fragmentation was done !
at barna.flux.simulator.SimulationPipeline.call(SimulationPipeline.java:438)
at barna.flux.simulator.SimulationPipeline.call(SimulationPipeline.java:53)
at barna.commons.launcher.Flux.main(Flux.java:196)}}

I have previously had success simulating much fewer reads (~1M) using the same parameter file. I performed the simulation using the following parameters:

NB_MOLECULES 40000000
TSS_MEAN NAN
POLYA_SCALE NAN
POLYA_SHAPE NAN

FRAG_SUBSTRATE RNA

RT_MOTIF default

FILTERING YES
SIZE_DISTRIBUTION N(285, 30)

PCR_DISTRIBUTION default

READ_NUMBER 160000000
READ_LENGTH 100
PAIRED_END YES
ERR_FILE 76
FASTA YES
UNIQUE_IDS YES

Hope you can help.

Best regards,

Jonas Andreas Sibbesen