All pending and approved links disappeared.

[Giovanni]

I have 2 directories connected to the same database but with different table prefix, the problem is that all links disappeared. Categories still shows but no links.
Checked prefix_link for and it's returning error:
Content visible to registered users only.What's the cause for this? And how can i resolve this issue.

[James]

check it off in phpmyadmin and choose repair.

Anything can cause it