Delete Qualification Information
If you have been able to connect to a share folder or download server, you may suddenly find yourself unable to connect.
Old information may have been registered in your credentials.
Please try clearing your credentials in the following way.
Access the Control Panel, go to User Accounts → Credentials Manager, and look at Windows Credentials on the Credentials Manager page.
There may be some old credentials left in the Windows credentials.
Please delete the old credentials of "yshare.sic.shibaura-it.ac.jp", "oshare.sic.shibaura-it.ac.jp", "*Session" or "download2.sic.shibaura-it.ac.jp", and restart your PC. Please restart your PC.
After that, please try to connect to the server again.
If this does not work, please try deleting the other credentials as well.