Adding Category

Hello,
In adding "New Revenue" page, I can't add new category, while I can add new Customer.
The same thing in "New Payment" page, I can't add new category but I can add new vendor.
Look at screen shots.

For more clarification, These options working well in the cloud, but not working on self-hosted version, I don't know why.
Clicking on + for adding category doesn't make any action, While + for customer or vendor working well!
Any one can help?

Go to Settings on the left - and then Categories - Add as Income type category for Revenues.

I know that, But I'm talking on an issue, not how to add categories.

Hello Mohammad,

Try to inspect the network of that page to see more details.

Regards