fix

iOSClient/Main/Menu/NCViewer+Menu.swift

@@ -172,6 +172,7 @@ extension NCViewer {
                         if let vcRename = UIStoryboard(name: "NCRenameFile", bundle: nil).instantiateInitialViewController() as? NCRenameFile {
                             
                             vcRename.metadata = metadata
+                            vcRename.disableChangeExt = true
 
                             let popup = NCPopupViewController(contentController: vcRename, popupWidth: 300, popupHeight: 360)
                                                         

iOSClient/Main/Rename file/NCRenameFile.swift

@@ -37,6 +37,7 @@ class NCRenameFile: UIViewController, UITextFieldDelegate {
     @IBOutlet weak var renameButton: UIButton!
 
     var metadata: tableMetadata?
+    var disableChangeExt: Bool = false
     
     // MARK: - Life Cycle
     
@@ -54,6 +55,10 @@ class NCRenameFile: UIViewController, UITextFieldDelegate {
             
             ext.text = metadata.ext
             ext.delegate = self
+            if disableChangeExt {
+                ext.isEnabled = false
+                ext.textColor = .lightGray
+            }
 
             if metadata.directory {