Hi @v3nom,
You are attempting to use a Snowplow release candidate (“rc”) - Snowplow rcs are designed for internal testing and often have significant changes relative to previous final releases. We don’t update the Snowplow documentation until the rc process has been finalized, so effectively you are using one version of Snowplow with documentation and example config files from another version.
The specific problem you are experiencing is that storage targets for StorageLoader in R88 are configured in a different way to R87.
To resolve this, simply use R87.