System not stable

System not stable

hi, I am a new user who just join & paid for Zoho CRM.

I found a problem that sometimes when I click a menu button for activities and potentials, the crm system cannot generate the page. (a rotation icon was showed on page)

I wait for half an hour and then go to visit the page again. The page becomes normal. But, the same issue happened again and again. I think my users cannot wait for it.

URL as below:

Would you please help to check the problem?

I am using Chrome browser, version 45.0.2454.85 m.

Thank you.

MPEP