diff --git a/osxphotos/photoinfo.py b/osxphotos/photoinfo.py
index b0060b37..61519eab 100644
--- a/osxphotos/photoinfo.py
+++ b/osxphotos/photoinfo.py
@@ -437,6 +437,7 @@ class PhotoInfo:
             if self.live_photo and not self.ismissing:
                 filename = pathlib.Path(self.path)
                 photopath = filename.parent.joinpath(f"{filename.stem}_3.mov")
+                photopath = str(photopath)
                 if not os.path.isfile(photopath):
                     # In testing, I've seen occasional missing movie for live photo
                     # these appear to be valid -- e.g. video component not yet downloaded from iCloud
@@ -680,7 +681,9 @@ class PhotoInfo:
         """ string representation of PhotoInfo object """
 
         date_iso = self.date.isoformat()
-        date_modified_iso = self.date_modified.isoformat() if self.date_modified else None
+        date_modified_iso = (
+            self.date_modified.isoformat() if self.date_modified else None
+        )
 
         info = {
             "uuid": self.uuid,
@@ -717,7 +720,9 @@ class PhotoInfo:
     def json(self):
         """ return JSON representation """
 
-        date_modified_iso = self.date_modified.isoformat() if self.date_modified else None
+        date_modified_iso = (
+            self.date_modified.isoformat() if self.date_modified else None
+        )
 
         pic = {
             "uuid": self.uuid,
diff --git a/osxphotos/photosdb.py b/osxphotos/photosdb.py
index 197e7fa2..20751b83 100644
--- a/osxphotos/photosdb.py
+++ b/osxphotos/photosdb.py
@@ -532,9 +532,17 @@ class PhotosDB:
             self._dbphotos[uuid]["modelID"] = row[1]
             self._dbphotos[uuid]["masterUuid"] = row[2]
             self._dbphotos[uuid]["filename"] = row[3]
-            self._dbphotos[uuid]["lastmodifieddate"] = (
-                datetime.fromtimestamp(row[4] + td) if row[4] is not None else None
-            )
+
+            # There are sometimes negative values for lastmodifieddate in the database
+            # I don't know what these mean but they will raise exception in datetime if
+            # not accounted for
+            if row[4] is not None and row[4] >= 0:
+                self._dbphotos[uuid]["lastmodifieddate"] = datetime.fromtimestamp(
+                    row[4] + td
+                )
+            else:
+                self._dbphotos[uuid]["lastmodifieddate"] = None
+
             self._dbphotos[uuid]["imageDate"] = datetime.fromtimestamp(row[5] + td)
             self._dbphotos[uuid]["mainRating"] = row[6]
             self._dbphotos[uuid]["hasAdjustments"] = row[7]
@@ -998,9 +1006,15 @@ class PhotosDB:
             info["masterUuid"] = None
             info["masterFingerprint"] = row[1]
             info["name"] = row[2]
-            info["lastmodifieddate"] = (
-                datetime.fromtimestamp(row[4] + td) if row[4] is not None else None
-            )
+
+            # There are sometimes negative values for lastmodifieddate in the database
+            # I don't know what these mean but they will raise exception in datetime if
+            # not accounted for
+            if row[4] is not None and row[4] >= 0:
+                info["lastmodifieddate"] = datetime.fromtimestamp(row[4] + td)
+            else:
+                info["lastmodifieddate"] = None
+                
             info["imageDate"] = datetime.fromtimestamp(row[5] + td)
             info["imageTimeZoneOffsetSeconds"] = row[6]
             info["hidden"] = row[9]