Opening reference and variants file ... OK Initializing fragment-to-contig distribution ... OK Initializing simulation threads ... OK Opening output file aedes_AaegL5_r1.fq.gz ... OK Opening output file aedes_AaegL5_r2.fq.gz .../home/osboxes/seqan/include/seqan/basic/basic_exception.h:363 FAILED! (Uncaught exception of type MasonIOException: Could not open right/single-end output file.)