This procedure explain how to fix the web application when it takes long

The root cause : insufficient server memory
Solution:
- Closing open application
- Free-up server memory fix.
- Increase the shutdown time limit
- Increase the shutdown time limit value of central administration application pool in IIS:
- Login to your SharePoint server which hosts Central Administration
- Open IIS manager >> Expand the server name and click on Application Pools.
- Locate the SharePoint Central Administration v4 application pool. Right click on it and choose Advanced Settings.
- In the Process Model section, set the Shutdown Time Limit to a greater value. E.g 900.

This could also happen when your SharePoint servers running out of disk space, database auto-growth setting isn’t enabled or your server antivirus preventing certain processes.