diff --git a/server/consumer.go b/server/consumer.go
index 3a46aaea197..080ec7a1fdc 100644
--- a/server/consumer.go
+++ b/server/consumer.go
@@ -4882,14 +4882,14 @@ func (o *consumer) loopAndGatherMsgs(qch chan struct{}) {
 			}
 			if err == ErrStoreMsgNotFound || err == errDeletedMsg || err == ErrStoreEOF || err == errMaxAckPending {
 				goto waitForMsgs
-			} else if err == errPartialCache {
-				s.Warnf("Unexpected partial cache error looking up message for consumer '%s > %s > %s'",
-					o.mset.acc, stream, o.cfg.Name)
-				goto waitForMsgs
-
 			} else {
-				s.Errorf("Received an error looking up message for consumer '%s > %s > %s': %v",
-					o.mset.acc, stream, o.cfg.Name, err)
+				if pmsg != nil {
+					s.Errorf("Received an error looking up message with sequence %d for consumer '%s > %s > %s': %v",
+						pmsg.seq, o.mset.acc, stream, o.cfg.Name, err)
+				} else {
+					s.Errorf("Received an error looking up message for consumer '%s > %s > %s': %v",
+						o.mset.acc, stream, o.cfg.Name, err)
+				}
 				goto waitForMsgs
 			}
 		}
diff --git a/server/filestore.go b/server/filestore.go
index 38b8dcd3449..940784f20e3 100644
--- a/server/filestore.go
+++ b/server/filestore.go
@@ -1521,7 +1521,7 @@ func (mb *msgBlock) rebuildStateLocked() (*LostStreamData, []uint64, error) {
 		// Do some quick sanity checks here.
 		if dlen < 0 || slen > (dlen-recordHashSize) || dlen > int(rl) || index+rl > lbuf || rl > rlBadThresh {
 			truncate(index)
-			return gatherLost(lbuf - index), tombstones, errBadMsg
+			return gatherLost(lbuf - index), tombstones, errBadMsg{mb.mfn, fmt.Sprintf("sanity check failed (dlen %d slen %d rl %d index %d lbuf %d)", dlen, slen, rl, index, lbuf)}
 		}
 
 		// Check for checksum failures before additional processing.
@@ -1539,7 +1539,7 @@ func (mb *msgBlock) rebuildStateLocked() (*LostStreamData, []uint64, error) {
 			checksum := hh.Sum(nil)
 			if !bytes.Equal(checksum, data[len(data)-recordHashSize:]) {
 				truncate(index)
-				return gatherLost(lbuf - index), tombstones, errBadMsg
+				return gatherLost(lbuf - index), tombstones, errBadMsg{mb.mfn, "invalid checksum"}
 			}
 			copy(mb.lchk[0:], checksum)
 		}
@@ -5291,7 +5291,7 @@ func (mb *msgBlock) slotInfo(slot int) (uint32, uint32, bool, error) {
 		}
 	}
 	if rl < msgHdrSize {
-		return 0, 0, false, errBadMsg
+		return 0, 0, false, errBadMsg{mb.mfn, fmt.Sprintf("length too short for slot %d", slot)}
 	}
 	return uint32(ri), rl, hashChecked, nil
 }
@@ -6840,7 +6840,7 @@ func (mb *msgBlock) indexCacheBuf(buf []byte) error {
 
 	// Sanity check here since we calculate size to allocate based on this.
 	if mbFirstSeq > (mbLastSeq + 1) { // Purged state first == last + 1
-		mb.fs.warn("indexCacheBuf corrupt state: mb.first %d mb.last %d", mbFirstSeq, mbLastSeq)
+		mb.fs.warn("indexCacheBuf corrupt state in %s: mb.first %d mb.last %d", mb.mfn, mbFirstSeq, mbLastSeq)
 		// This would cause idxSz to wrap.
 		return errCorruptState
 	}
@@ -6905,7 +6905,7 @@ func (mb *msgBlock) indexCacheBuf(buf []byte) error {
 
 		// Do some quick sanity checks here.
 		if dlen < 0 || slen > (dlen-recordHashSize) || dlen > int(rl) || index+rl > lbuf || rl > rlBadThresh {
-			mb.fs.warn("indexCacheBuf corrupt record state: dlen %d slen %d index %d rl %d lbuf %d", dlen, slen, index, rl, lbuf)
+			mb.fs.warn("indexCacheBuf corrupt record state in %s: dlen %d slen %d index %d rl %d lbuf %d", mb.mfn, dlen, slen, index, rl, lbuf)
 			// This means something is off.
 			// TODO(dlc) - Add into bad list?
 			return errCorruptState
@@ -7423,7 +7423,6 @@ func (mb *msgBlock) fetchMsgEx(seq uint64, sm *StoreMsg, doCopy bool) (*StoreMsg
 
 var (
 	errNoCache       = errors.New("no message cache")
-	errBadMsg        = errors.New("malformed or corrupt message")
 	errDeletedMsg    = errors.New("deleted message")
 	errPartialCache  = errors.New("partial cache")
 	errNoPending     = errors.New("message block does not have pending data")
@@ -7441,6 +7440,17 @@ var (
 	errStateTooBig   = errors.New("store state too big for optional write")
 )
 
+type (
+	errBadMsg struct{ fn, detail string }
+)
+
+func (e errBadMsg) Error() string {
+	if e.detail != _EMPTY_ {
+		return fmt.Sprintf("malformed or corrupt message in %s: %s", filepath.Base(e.fn), e.detail)
+	}
+	return fmt.Sprintf("malformed or corrupt message in %s", filepath.Base(e.fn))
+}
+
 const (
 	// "Checksum bit" is used in "mb.cache.idx" for marking messages that have had their checksums checked.
 	cbit = 1 << 31
@@ -7644,7 +7654,7 @@ func (mb *msgBlock) msgFromBufNoCopy(buf []byte, sm *StoreMsg, hh hash.Hash64) (
 // Lock should be held.
 func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCopy bool) (*StoreMsg, error) {
 	if len(buf) < emptyRecordLen {
-		return nil, errBadMsg
+		return nil, errBadMsg{mb.mfn, "record too short"}
 	}
 	var le = binary.LittleEndian
 
@@ -7656,7 +7666,7 @@ func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCop
 	slen := int(le.Uint16(hdr[20:]))
 	// Simple sanity check.
 	if dlen < 0 || slen > (dlen-recordHashSize) || dlen > int(rl) || int(rl) > len(buf) || rl > rlBadThresh {
-		return nil, errBadMsg
+		return nil, errBadMsg{mb.mfn, fmt.Sprintf("sanity check failed (dlen %d slen %d rl %d buf %d)", dlen, slen, rl, buf)}
 	}
 	data := buf[msgHdrSize : msgHdrSize+dlen]
 	// Do checksum tests here if requested.
@@ -7670,7 +7680,7 @@ func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCop
 			hh.Write(data[slen : dlen-recordHashSize])
 		}
 		if !bytes.Equal(hh.Sum(nil), data[len(data)-8:]) {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid checksum"}
 		}
 	}
 	seq := le.Uint64(hdr[4:])
@@ -7689,18 +7699,18 @@ func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCop
 	// layers and for us to be safe to expire, and recycle, the large msgBlocks.
 	end := dlen - 8
 	if len(data) < end {
-		return nil, errBadMsg
+		return nil, errBadMsg{mb.mfn, "invalid data length"}
 	}
 
 	if hasHeaders {
 		if slen+4 > len(data) {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid subject length greataer than data length"}
 		}
 		hl := le.Uint32(data[slen:])
 		bi := slen + 4
 		li := bi + int(hl)
 		if bi > end {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid buffer index"}
 		}
 		if doCopy {
 			sm.buf = append(sm.buf, data[bi:end]...)
@@ -7709,13 +7719,13 @@ func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCop
 		}
 		li, end = li-bi, end-bi
 		if li > len(sm.buf) || end > len(sm.buf) {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid message length or end greater than buffer length"}
 		}
 		sm.hdr = sm.buf[0:li:li]
 		sm.msg = sm.buf[li:end]
 	} else {
 		if slen > end {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid subject length greater than end"}
 		}
 		if doCopy {
 			sm.buf = append(sm.buf, data[slen:end]...)
@@ -7724,14 +7734,14 @@ func (mb *msgBlock) msgFromBufEx(buf []byte, sm *StoreMsg, hh hash.Hash64, doCop
 		}
 		mlen := end - slen
 		if mlen > len(sm.buf) {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid message length greater than buffer length"}
 		}
 		sm.msg = sm.buf[0:mlen]
 	}
 	sm.seq, sm.ts = seq, ts
 	if slen > 0 {
 		if slen > len(data) {
-			return nil, errBadMsg
+			return nil, errBadMsg{mb.mfn, "invalid subject length greater than data length"}
 		}
 		if doCopy {
 			// Make a copy since sm.subj lifetime may last longer.