Hi @Abd_25, thanks for posting on the forum and welcome to the SimScale Community 
If the mesh is too large, it will take longer to load. I can see it’s loading from the blue passing line on top of your screen.
In case the mesh is large, you just need to wait and it will appear at some point. If not, you can try clearing your browser’s cached data and try again. Please share a project link so we can try loading your mesh on our end.
Cheers,
Igor