Why can't I add more than 252 names to my PAWriter file?
I guess you mean 252 people.
There is no such limit. In fact, there is no practical limit to the number of people that can be added to a PAWriter file. I have more than 44,000 people in my main file.
Please describe exactly what happened, so I have a better idea of the problem, and can help solve it.
(Perhaps you mean 252 characters in a person's name? Or something similar? Each piece of a name -- given name, surname, etc. -- is limited to 31 characters, and you can enter a surname, one to five given names, a title, a suffix and a nickname. That can add up to more than 252 characters.)