diff --git a/chrome/content/zotero/xpcom/data/dataObjects.js b/chrome/content/zotero/xpcom/data/dataObjects.js
index 548d8d6bd..40512140e 100644
--- a/chrome/content/zotero/xpcom/data/dataObjects.js
+++ b/chrome/content/zotero/xpcom/data/dataObjects.js
@@ -329,9 +329,10 @@ Zotero.DataObjects.prototype.getLibraryAndKeyFromID = function (id) {
 
 
 Zotero.DataObjects.prototype.getIDFromLibraryAndKey = function (libraryID, key) {
-	if (!libraryID) {
-		throw new Error("libraryID not provided");
-	}
+	if (!libraryID) throw new Error("Library ID not provided");
+	// TEMP: Just warn for now
+	//if (!key) throw new Error("Key not provided");
+	if (!key) Zotero.logError("Key not provided");
 	return (this._objectIDs[libraryID] && this._objectIDs[libraryID][key])
 		? this._objectIDs[libraryID][key] : false;
 }
diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 0c1058ffc..0bc14ddb9 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -1373,7 +1373,9 @@ Zotero.Item.prototype._saveData = Zotero.Promise.coroutine(function* (env) {
 	
 	// Parent item (DB update is done below after collection removals)
 	var parentItemKey = this.parentKey;
-	var parentItemID = this.ObjectsClass.getIDFromLibraryAndKey(this.libraryID, parentItemKey) || null;
+	var parentItemID = parentItemKey
+		? (this.ObjectsClass.getIDFromLibraryAndKey(this.libraryID, parentItemKey) || null)
+		: null;
 	if (this._changed.parentKey) {
 		if (isNew) {
 			if (!parentItemID) {