BaseRecalibrator Step Error

I get below error with workflow step "germline_single_sample_workflow.BaseRecalibrator"

java.lang.IllegalArgumentException: Could not build the path "["...broad-references/hg38/v0/Mills_and_1000G_gold_standard.indels.hg38.vcf.gz","...broad-references/hg38/v0/Homo_sapiens_assembly38.known_indels.vcf.gz"]". It may refer to a filesystem not supported by this instance of Cromwell. Supported filesystems are: Google Cloud Storage. Failures: Google Cloud Storage: The specified GCS path '["...broad-references/hg38/v0/Mills_and_1000G_gold_standard.indels.hg38.vcf.gz","...broad-references/hg38/v0/Homo_sapiens_assembly38.known_indels.vcf.gz"]' does not parse as a URI. Illegal character in scheme name at index 0: %5B%22...broad-references/hg38/v0/Mills_and_1000G_gold_standard.indels.hg38.vcf.gz%22,%22...broad-references/hg38/v0/Homo_sapiens_assembly38.known_indels.vcf.gz%22%5D (IllegalArgumentException)

I have removed the google storage prefix from above message, to pass through validation.