diff --git a/chrome/content/zotero/xpcom/data/dataObject.js b/chrome/content/zotero/xpcom/data/dataObject.js
index 728e85175..bebcb6e2a 100644
--- a/chrome/content/zotero/xpcom/data/dataObject.js
+++ b/chrome/content/zotero/xpcom/data/dataObject.js
@@ -584,7 +584,11 @@ Zotero.DataObject.prototype.save = Zotero.Promise.coroutine(function* (options)
 			Zotero.debug(e2, 1);
 		})
 		.then(function() {
-			Zotero.debug(e, 1);
+			// Don't log expected errors
+			if (e.name != 'ZoteroUnknownFieldError'
+					&& e.name != 'ZoteroMissingObjectError') {
+				Zotero.debug(e, 1);
+			}
 			throw e;
 		})
 	});
diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index eeba8e79e..0042b84f8 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -1350,8 +1350,10 @@ Zotero.Item.prototype._saveData = Zotero.Promise.coroutine(function* (env) {
 		if (isNew) {
 			if (!parentItemID) {
 				// TODO: clear caches?
-				let msg = parentItemKey + " is not a valid item key";
-				throw new Zotero.Error(msg, "MISSING_OBJECT");
+				let msg = "Parent item " + this.libraryID + "/" + parentItemKey + " not found";
+				let e = new Error(msg);
+				e.name = "ZoteroMissingObjectError";
+				throw e;
 			}
 			
 			let newParentItemNotifierData = {};
@@ -1372,8 +1374,10 @@ Zotero.Item.prototype._saveData = Zotero.Promise.coroutine(function* (env) {
 			if (parentItemKey) {
 				if (!parentItemID) {
 					// TODO: clear caches
-					let msg = "Cannot set source to invalid item " + parentItemKey;
-					throw new Zotero.Error(msg, "MISSING_OBJECT");
+					let msg = "Parent item " + this.libraryID + "/" + parentItemKey + " not found";
+					let e = new Error(msg);
+					e.name = "ZoteroMissingObjectError";
+					throw e;
 				}
 				
 				let newParentItemNotifierData = {};