Joomla 2.5 install errors

[muddauber]

Phoco Download worked fine with Joomla 1.5.26. Did the jUpgrade and all else works but
Phoco Download. I did upload the latest version.

Errors on web page:

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in /home/mydomain/public_html/jupgrade/libraries/joomla/database/database/mysqli.php on line 263

In categories, files admin section I get:
Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in /home/mydomain/public_html/jupgrade/libraries/joomla/database/database/mysqli.php on line 263

[Jan]

Hi, see:
https://www.phoca.cz/documents/16-joomla ... ent-errors
Jan