I have a problem with new members sign in.

situation:

Our new project member had registered his  account's password through the invitation mail.

after then the web page was moved to ZOHO top page.

https://www.zoho.com/jp/projects/

He clicked "sign in" which is in right side above.

But the input form (e-mail and password ) is not indicated.

He tried several web browsers but result was same.

He still can not reach my project web page.

I would like to know that what should I check to solve this problem.

Additional information:

The new member is in different company and different facility.

The input form (e-mail and password ) is indicated on my page any time.