Dear Ahmad Mahid,
Thank you for your report.
Is this a Revit API issue, or an end user question?
Are you doing anything programmatically, or just using the standard Revit user interface?
If you are not doing anything programmatically, please note that this discussion forum is dedicated to programming Revit using the Revit API.
Therefore, you cannot expect an answer to a question such as yours relating to installation, product usage or end user support issues here.
You should try one of the non-API Revit product support discussion forums instead for that:
https://forums.autodesk.com/t5/revit-api-forum/this-forum-is-for-revit-api-programming-questions-not...
The people there are much better equipped to answer your question than us programming nerds.
I hope this clarifies. Thank you for your cooperation and understanding.
If you are doing it programmatically, please submit a minimal reproducible case with exact steps to reproduce the problem that I can share with the development team:
http://thebuildingcoder.typepad.com/blog/about-the-author.html#1b
Thank you!
Best regards,
Jeremy