Maybe you can modify the configure file manually, but it is definitely not safe.
I met this problem when I use 2.5.17, If you are use 2.5.17, you can try to upgrade to 2.5.19. Maybe it will be solved.
I met this problem when I use 2.5.17, If you are use 2.5.17, you can try to upgrade to 2.5.19. Maybe it will be solved.