SnpSift Annotate

Dear all,
I am receiving this error when trying to apply SnpSift Annotate to a hg38 VCF file, using dbSNP_146_hg38.vcf as reference downloaded from Galaxy shared data.

Picked up _JAVA_OPTIONS: -Xmx7g -Xms256m
Fatal error: Database file name not found. Missing ‘database.null.GRCh37’ entry in SnpEff’s config file?

The tool was working for me before using the same sequencing data and I’ve not changed any of the settings. Any suggestions would be very welcome, thank you