diff --git a/agglayer/proof_generation_error.go b/agglayer/proof_generation_error.go
index fa7012f74..50858c2e5 100644
--- a/agglayer/proof_generation_error.go
+++ b/agglayer/proof_generation_error.go
@@ -38,6 +38,15 @@ type PPError interface {
 	String() string
 }
 
+type GenericError struct {
+	Key    string
+	Values string
+}
+
+func (p *GenericError) String() string {
+	return fmt.Sprintf("Generic error: %s: %s", p.Key, p.Values)
+}
+
 // ProofGenerationError is a struct that represents an error that occurs when generating a proof.
 type ProofGenerationError struct {
 	GenerationType string
diff --git a/agglayer/types.go b/agglayer/types.go
index 9a56d8786..dbeeed4a6 100644
--- a/agglayer/types.go
+++ b/agglayer/types.go
@@ -654,7 +654,9 @@ func (c *CertificateHeader) UnmarshalJSON(data []byte) error {
 
 				ppError = p
 			default:
-				return fmt.Errorf("invalid error type: %s", key)
+				valueStr, _ := json.Marshal(value)
+
+				ppError = &GenericError{Key: key, Values: string(valueStr)}
 			}
 		}