Yes, you are missing the bed_to_bigwig converter.
If you haven't made changes to your datatypes_conf.xml file, you can just copy datatypes_conf.xml.sample to datatypes_conf.xml to get the needed converters.
If you've made changes to datatypes_conf.xml, you'll need to manually add the needed converters. We recently transitioned all the *_to_summary_tree converters to *_to_bigwig, so you'll want to remove the summary_tree converters and replace them with the bigwig converters.