This indicates that dap is unable to connect to your database.

Possible causes:
1) Something changed (hostmove / domain move etc) that is preventing dap from connecting to the dap database on your site.
FTP to your site. Check /dap/dap-config.php and wp-config.php and make sure that the database params in both dap-config.php and wp-config.php match.

If they dont, update the database name/id/password in /dap/dap-config.php to match the WP database id/password/name.

Now see if the memory issues go away.

2) allocated memory not enough

You can add this to wp-config.php to update the limit:

ini_set('memory_limit', '64M');

3) too many active plugins and some plugins using up a lot of memory

So, deactivate all other plugins except dap. Then activate one by one to check which one is causing the issue.

If none of the above helps, pls do this:
1) FTP to your site

2) Rename /dap/dap-config.php to /dap/dap-config.php.BAK

3) Now visit this URL in a browser:
http://YOURSITE.com/dap/install/install2.php (replace YOURSITE.com with the name of your site)

4) Fill in the details. If you do not the database name, username etc, you can get it from your wp-config.php file at the root of your blog installation.

5) Click on start installation.

6) Now go to WP admin -> plugins and activate dap live links.

That's it. Now check if the memory error still occurs.