diff --git a/core/src/main/java/bisq/core/account/witness/AccountAgeWitnessService.java b/core/src/main/java/bisq/core/account/witness/AccountAgeWitnessService.java
index 3e5a948f64d..7fe43ecc7d2 100644
--- a/core/src/main/java/bisq/core/account/witness/AccountAgeWitnessService.java
+++ b/core/src/main/java/bisq/core/account/witness/AccountAgeWitnessService.java
@@ -65,6 +65,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Random;
 import java.util.concurrent.TimeUnit;
@@ -616,6 +617,7 @@ public List<TraderDataItem> getTraderPaymentAccounts(long safeDate, PaymentMetho
                 .filter(this::hasChargebackRisk)
                 .filter(this::isBuyerWinner)
                 .flatMap(this::getTraderData)
+                .filter(Objects::nonNull)
                 .filter(traderDataItem ->
                         !signedWitnessService.isSignedAccountAgeWitness(traderDataItem.getAccountAgeWitness()))
                 .filter(traderDataItem -> traderDataItem.getAccountAgeWitness().getDate() < safeDate)
diff --git a/core/src/main/java/bisq/core/support/dispute/mediation/MediationDisputeList.java b/core/src/main/java/bisq/core/support/dispute/mediation/MediationDisputeList.java
index 2b58f98d586..ce45e2fede5 100644
--- a/core/src/main/java/bisq/core/support/dispute/mediation/MediationDisputeList.java
+++ b/core/src/main/java/bisq/core/support/dispute/mediation/MediationDisputeList.java
@@ -18,7 +18,6 @@
 package bisq.core.support.dispute.mediation;
 
 import bisq.core.proto.CoreProtoResolver;
-import bisq.core.support.SupportType;
 import bisq.core.support.dispute.Dispute;
 import bisq.core.support.dispute.DisputeList;
 
@@ -34,8 +33,6 @@
 import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
 @Slf4j
 @ToString
 /*
@@ -69,9 +66,6 @@ private MediationDisputeList(Storage<MediationDisputeList> storage, List<Dispute
 
     @Override
     public Message toProtoMessage() {
-
-        list.forEach(dispute -> checkArgument(dispute.getSupportType().equals(SupportType.MEDIATION), "Support type has to be MEDIATION"));
-
         return protobuf.PersistableEnvelope.newBuilder().setMediationDisputeList(protobuf.MediationDisputeList.newBuilder()
                 .addAllDispute(ProtoUtil.collectionToProto(new ArrayList<>(list)))).build();
     }
@@ -82,11 +76,7 @@ public static MediationDisputeList fromProto(protobuf.MediationDisputeList proto
         List<Dispute> list = proto.getDisputeList().stream()
                 .map(disputeProto -> Dispute.fromProto(disputeProto, coreProtoResolver))
                 .collect(Collectors.toList());
-
-        list.forEach(e -> {
-            checkArgument(e.getSupportType().equals(SupportType.MEDIATION), "Support type has to be MEDIATION");
-            e.setStorage(storage);
-        });
+        list.forEach(e -> e.setStorage(storage));
         return new MediationDisputeList(storage, list);
     }
 }