Change languages

First of all I download “sc_tickets” and add Arabic language like this


So, to make Arabic language the default I must change in first line to 1 like this:

But after that I face this error like this:

So, If I changed the number to 2 the error message disappear, But get En. language the default


The second issue:
After that if I choose another language it display En. language only like this:

So, If I change first line number to 1 like this:

it display error like this:

But it display only Ar. Language like this:

Can you help me please?
Thanks in advance