I had deleted one user from my existing and now trying to add new one but getting message that I have reached Maximum limit of creating users.

I had deleted one user from my existing and now trying to add new one but getting message that I have reached Maximum limit of creating users.

I had deleted one user from my existing and now trying to add new one but getting message that I have reached Maximum limit of creating users, whereas I have maximum limit of 5 users and currently using 4 users and 1 user is available. 

Regards.