CombineGVCFs error

Hi, I am getting error message "Problem detecting index type" while combining 200 GVCFs generated by HaplotypeCaller (gatk 3.5). Can you suggest how can i identify source of this error or if this is anything known.

Thanks

INFO 12:09:45,366 HelpFormatter - --------------------------------------------------------------------------------
INFO 12:09:45,536 HelpFormatter - The Genome Analysis Toolkit (GATK) v3.5-0-g36282e4, Compiled 2015/11/25 04:03:56
INFO 12:09:45,536 HelpFormatter - Copyright (c) 2010 The Broad Institute
INFO 12:09:45,536 HelpFormatter - For support and documentation go to http://www.broadinstitute.org/gatk
INFO 12:09:45,540 HelpFormatter - Program Args: -R ref.fasta -T CombineGVCFs -V gVCF-f1.list -o gVCF-f1.g.vcf
INFO 12:09:45,545 HelpFormatter - Date/Time: 2016/08/09 12:09:45
INFO 12:09:45,545 HelpFormatter - --------------------------------------------------------------------------------
INFO 12:09:45,546 HelpFormatter - --------------------------------------------------------------------------------
INFO 12:13:56,334 GenomeAnalysisEngine - Strictness is SILENT
INFO 12:13:56,953 GenomeAnalysisEngine - Downsampling Settings: Method: BY_SAMPLE, Target Coverage: 1000
INFO 12:23:14,035 RMDTrackBuilder - Writing Tribble index to disk for file 1A.g.vcf.idx
INFO 12:27:51,742 RMDTrackBuilder - Writing Tribble index to disk for file 11A.g.vcf.idx
INFO 12:29:15,840 RMDTrackBuilder - Writing Tribble index to disk for file 8A.g.vcf.idx
INFO 12:30:32,400 RMDTrackBuilder - Writing Tribble index to disk for file 9A.g.vcf.idx
INFO 12:32:22,639 RMDTrackBuilder - Writing Tribble index to
disk for file 5A.g.vcf.idx
INFO 12:32:27,187 GATKRunReport - Uploaded run statistics report to AWS S3

ERROR ------------------------------------------------------------------------------------------

ERROR A USER ERROR has occurred (version 3.5-0-g36282e4):

ERROR

ERROR This means that one or more arguments or inputs in your command are incorrect.

ERROR The error message below tells you what is the problem.

ERROR

ERROR If the problem is an invalid argument, please check the online documentation guide

ERROR (or rerun your command with --help) to view allowable command-line arguments for this tool.

ERROR

ERROR Visit our website and forum for extensive documentation and answers to

ERROR commonly asked questions http://www.broadinstitute.org/gatk

ERROR

ERROR Please do NOT post this error to the GATK forum unless you have really tried to fix it yourself.

ERROR

ERROR MESSAGE: Problem detecting index type

ERROR ------------------------------------------------------------------------------------------