diff --git a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/MediaController.js b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/MediaController.js
index a10b4573d27c9c06f34d5f82c897882b64dc34e2..6b4f6a20923dd0d215c250f5018b768294cc03ce 100644
--- a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/MediaController.js
+++ b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/MediaController.js
@@ -311,7 +311,7 @@ module.exports = class MediaController {
   _handleError (error) {
     Logger.error("[mcs-controller] Controller received error", error);
     // Checking if the error needs to be wrapped into a JS Error instance
-    if (isError(error)) {
+    if (!isError(error)) {
       error = new Error(error);
     }
     return error;
diff --git a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/media-server.js b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/media-server.js
index f74705ece89532676d7a233639f585183f965ba0..1d3d4ae50c3e07dd825026e1ac926045b9c3c43b 100644
--- a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/media-server.js
+++ b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/media/media-server.js
@@ -387,7 +387,7 @@ module.exports = class MediaServer extends EventEmitter {
 
   _handleError(error) {
     // Checking if the error needs to be wrapped into a JS Error instance
-    if (isError(error)) {
+    if (!isError(error)) {
       error = new Error(error);
     }
 
diff --git a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/MediaSession.js b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/MediaSession.js
index 0fc4221720dbf0bd9aea2fe8777b4620b97b0b62..f9652525bd5412ef0002723029d715793c5f9067 100644
--- a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/MediaSession.js
+++ b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/MediaSession.js
@@ -102,7 +102,7 @@ module.exports = class MediaSession {
   _handleError (error) {
     Logger.error("[mcs-media-session] SFU MediaSession received an error", error);
     // Checking if the error needs to be wrapped into a JS Error instance
-    if (isError(error)) {
+    if (!isError(error)) {
       error = new Error(error);
     }
     this._status = C.STATUS.STOPPED;
diff --git a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SfuUser.js b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SfuUser.js
index 44c547f29564bd48e3985af7618a711cd41bf84a..6440fca18e78240ad88a8af32560f5c31010413e 100644
--- a/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SfuUser.js
+++ b/labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SfuUser.js
@@ -186,7 +186,7 @@ module.exports = class SfuUser extends User {
   handleError (error) {
     Logger.error("[mcs-sfu-user] SFU User received error", error);
     // Checking if the error needs to be wrapped into a JS Error instance
-    if (isError(error)) {
+    if (!isError(error)) {
       error = new Error(error);
     }
     this._status = C.STATUS.STOPPED;
diff --git a/labs/bbb-webrtc-sfu/lib/screenshare/screenshare.js b/labs/bbb-webrtc-sfu/lib/screenshare/screenshare.js
index e526f1519a05ebe75aeb6098a0a888e5df220981..5d0b6e46e5560ef99c0cf4a00425d4e65f7a4edd 100644
--- a/labs/bbb-webrtc-sfu/lib/screenshare/screenshare.js
+++ b/labs/bbb-webrtc-sfu/lib/screenshare/screenshare.js
@@ -227,14 +227,14 @@ module.exports = class Screenshare extends EventEmitter {
     }
   }
 
-  async _startViewer(connectionId, voiceBridge, sdp, callerName, presenterEndpoint, callback) {
+  async _startViewer(connectionId, voiceBridge, sdpOffer, callerName, presenterEndpoint, callback) {
     Logger.info("[screenshare] Starting viewer", callerName, "for voiceBridge", this._voiceBridge);
     // TODO refactor the callback handling
     let _callback = function(){};
-    let sdpAnswer, sdpOffer;
+    let sdpAnswer;
 
     if (FORCE_H264) {
-      sdpOffer = h264_sdp.transform(sdp);
+      sdpOffer = h264_sdp.transform(sdpOffer);
     }
 
     this._viewersCandidatesQueue[callerName] = [];