@sp_user, those errors indicate that the HTTP requests were sent to the collector at the path /<vendor_name>/<version>. The Snowplow collector has many default endpoints and any endpoint the HTTP request was sent to that is not either default or not customary configured will be rejected at validation step with the error message “Payload with vendor_name and version not supported by this version of Scala Common Enrich”.
The default endpoints are related to the collector adaptor dedicated to the specific type of events. For example, POST events would have to be sent to /com.snowplowanalytics.snowplow/tp2 (vendor com.snowplowanalytics.snowplow, version tp2), redirects would be sent to /r/tp2, and so on.
You cannot stop that kind of bad data from reaching your bad bucket. Various bots searching for server vulnerability will be poking into different endpoints. However, this bad data could be easily ignored with your analytics tool based on the error description “Payload with vendor”. This is explained, for example, here: