Thread:Project:Support desk/Duplicate article name in Category page

Hi, i imported few thousand article to my mediawiki site. At the time of importing the articles all the article had a common category. then i replaced that category with a new one. i used 'pywikibot replace.py' to replace the category. now the problem is the previous category shows that it has has pages but it is not. and some cases it shows duplicate page names. I used the Manual:rebuildall.php but it did not solve the issues. what might be the reason of this and what is the solution?