Envoy proxy container crashes after EnvoyFilter applied

istio-proxy container crashes immediately after applying an EnvoyFilter, caused by invalid filter configuration that Envoy cannot parse, missing required fields in filter config, or references to non-existent clusters (e.g., in Lua httpCall)

Retrieve logs from the crashed container using --previous flag. Look for parse errors, missing required configuration fields, or invalid cluster references. Validate EnvoyFilter YAML syntax and Envoy-specific configuration. Remove or correct the problematic EnvoyFilter.