diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index 2d111d5..673c130 100644
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -218,30 +218,10 @@ namespace Checkpoints
     }
 
     // Check against synchronized checkpoint
+    // Disabled: master key removed in V5, no new sync checkpoints possible.
+    // Always returns true to prevent stale DB-persisted checkpoints from blocking IBD.
     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
     {
-        if (fTestNet) return true; // Testnet has no checkpoints
-        int nHeight = pindexPrev->nHeight + 1;
-
-        LOCK(cs_hashSyncCheckpoint);
-        // sync-checkpoint should always be accepted block
-        assert(mapBlockIndex.count(hashSyncCheckpoint));
-        const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
-
-        if (nHeight > pindexSync->nHeight)
-        {
-            // trace back to same height as sync-checkpoint
-            const CBlockIndex* pindex = pindexPrev;
-            while (pindex->nHeight > pindexSync->nHeight)
-                if (!(pindex = pindex->pprev))
-                    return error("CheckSync: pprev null - block index structure failure");
-            if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
-                return false; // only descendant of sync-checkpoint can pass check
-        }
-        if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
-            return false; // same height with sync-checkpoint
-        if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
-            return false; // lower height than sync-checkpoint
         return true;
     }
 
@@ -361,8 +341,8 @@ namespace Checkpoints
     bool IsMatureSyncCheckpoint()
     {
         LOCK(cs_hashSyncCheckpoint);
-        // sync-checkpoint should always be accepted block
-        assert(mapBlockIndex.count(hashSyncCheckpoint));
+        if (!mapBlockIndex.count(hashSyncCheckpoint))
+            return true; // no valid sync checkpoint, treat as mature
         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
diff --git a/src/main.cpp b/src/main.cpp
index de354f1..af06116 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2471,18 +2471,10 @@ bool CBlock::AcceptBlock()
         }
     }
 
-    // Before fork: enforce sync checkpoints for historical chain integrity
-    // After fork: no sync checkpoint enforcement (decentralized)
-    if (nHeight < FORK_HEIGHT_V5)
-    {
-        bool cpSatisfies = Checkpoints::CheckSync(hash, pindexPrev);
-
-        if (CheckpointsMode == Checkpoints::STRICT && !cpSatisfies)
-            return error("AcceptBlock() : rejected by synchronized checkpoint");
-
-        if (CheckpointsMode == Checkpoints::ADVISORY && !cpSatisfies)
-            strMiscWarning = _("WARNING: syncronized checkpoint violation detected, but skipped!");
-    }
+    // Sync checkpoint enforcement is disabled:
+    // - Master key was removed in V5 fork, no new sync checkpoints will be broadcast
+    // - Hardcoded checkpoints already guarantee chain integrity
+    // - The persisted hashSyncCheckpoint in LevelDB blocks IBD from progressing
 
     // Enforce rule that the coinbase starts with serialized block height
     CScript expect = CScript() << nHeight;
diff --git a/src/txdb-leveldb.cpp b/src/txdb-leveldb.cpp
index 7e95019..cc27b16 100644
--- a/src/txdb-leveldb.cpp
+++ b/src/txdb-leveldb.cpp
@@ -484,10 +484,17 @@ bool CTxDB::LoadBlockIndex()
       hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(nBestChainTrust).ToString().c_str(),
       DateTimeStrFormat("%x %H:%M:%S", pindexBest->GetBlockTime()).c_str());
 
-    // triangles: load hashSyncCheckpoint
+    // triangles: load hashSyncCheckpoint (best-effort, non-fatal)
     if (!ReadSyncCheckpoint(Checkpoints::hashSyncCheckpoint))
-        return error("CTxDB::LoadBlockIndex() : hashSyncCheckpoint not loaded");
-    printf("LoadBlockIndex(): synchronized checkpoint %s\n", Checkpoints::hashSyncCheckpoint.ToString().c_str());
+        printf("LoadBlockIndex(): no sync checkpoint in DB, using default\n");
+    else
+        printf("LoadBlockIndex(): synchronized checkpoint %s\n", Checkpoints::hashSyncCheckpoint.ToString().c_str());
+    // If the stored checkpoint isn't in our index, reset to genesis so we don't assert-crash
+    if (!mapBlockIndex.count(Checkpoints::hashSyncCheckpoint))
+    {
+        printf("LoadBlockIndex(): sync checkpoint not in index, resetting to genesis\n");
+        Checkpoints::hashSyncCheckpoint = (!fTestNet ? hashGenesisBlockOfficial : hashGenesisBlockTestNet);
+    }
 
     // Load bnBestInvalidTrust, OK if it doesn't exist
     CBigNum bnBestInvalidTrust;