diff --git a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/MimeTypeUtils.java b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/MimeTypeUtils.java
index cee7ef4bb4..aa8a2d5277 100644
--- a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/MimeTypeUtils.java
+++ b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/MimeTypeUtils.java
@@ -44,8 +44,14 @@ public class MimeTypeUtils {
     };
 
     public Boolean extensionMatchMimeType(String mimeType, String finalExtension) {
-        if(EXTENSIONS_MIME.containsKey(finalExtension.toLowerCase())) {
-            return EXTENSIONS_MIME.get(finalExtension.toLowerCase()).equalsIgnoreCase(mimeType);
+        if(EXTENSIONS_MIME.containsKey(finalExtension.toLowerCase()) &&
+            EXTENSIONS_MIME.get(finalExtension.toLowerCase()).equalsIgnoreCase(mimeType)) {
+            return true;
+        } else if(EXTENSIONS_MIME.containsKey(finalExtension.toLowerCase() + 'x') &&
+                    EXTENSIONS_MIME.get(finalExtension.toLowerCase() + 'x').equalsIgnoreCase(mimeType)) {
+            //Exception for MS Office files named with old extension but using internally the new mime type
+            //e.g. a file named with extension `ppt` but has the content of a `pptx`
+            return true;
         }
 
         return false;
diff --git a/bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy b/bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy
index 346cba832a..9b3602ede6 100755
--- a/bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy
+++ b/bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy
@@ -45,7 +45,6 @@ import org.bigbluebutton.web.services.turn.RemoteIceCandidate
 import org.json.JSONArray
 
 import javax.servlet.ServletRequest
-import java.util.regex.*
 
 class ApiController {
   private static final Integer SESSION_TIMEOUT = 14400  // 4 hours