[Help me] Can not use the "Issues" feature

[Help me] Can not use the "Issues" feature

Hi,

I am approaching zoho project software, the first two days were very good, but now I get an error in the "Issues" tab.

In detail:

When clicking on the "Issues" tab, the software does not display the common interface (displaying the list of old Issue and button to create new issue). 
It shows up as the image below:


I tried activating the "Issues" feature by clicking on the "Turn on" button as shown below, but that does not help either


Please help me !!!!!!!!!!!!!!!!!!!!!!!!!

Thanks in advance,

Viet TQ