Problem with most plugins

I tried to install different plugins. I downloaded them, placed them under the mod folder and after pressing "enable" a certain plugin within the Tool administration menu I continuosly got a black screen. I even got a blank screen when trying to enable all applications. No erros, no reports. So I went to the my XAMPP console error log,  and this is what I found:

[Sun Apr 12 01:46:34 2009] [error] [client ::1] File does not exist: /Applications/xampp/xamppfiles/htdocs/elgg/_graphics/icons/default/topbar.png, referer: http://localhost/elgg/pg/admin/plugins/
[Sun Apr 12 01:46:43 2009] [error] [client ::1] WARNING: 2009-04-12 01:46:43 (EDT): "file_get_contents(/Applications/xampp/xamppfiles/htdocs/elgg/mod/mod/manifest.xml) [<a href='function.file-get-contents'>function.file-get-contents</a>]: failed to open stream: No such file or directory" in file /Applications/xampp/xamppfiles/htdocs/elgg/engine/lib/plugins.php (line 324), referer: http://localhost/elgg/pg/admin/statistics/
[Sun Apr 12 01:46:43 2009] [error] [client ::1] File does not exist: /Applications/xampp/xamppfiles/htdocs/elgg/_graphics/icons/default/topbar.png, referer: http://localhost/elgg/pg/admin/plugins/
[Sun Apr 12 01:46:50 2009] [error] [client ::1] WARNING: 2009-04-12 01:46:50 (EDT): "file_get_contents(/Applications/xampp/xamppfiles/htdocs/elgg/mod/mod/manifest.xml) [<a href='function.file-get-contents'>function.file-get-contents</a>]: failed to open stream: No such file or directory" in file /Applications/xampp/xamppfiles/htdocs/elgg/engine/lib/plugins.php (line 324), referer: http://localhost/elgg/pg/admin/plugins/
[Sun Apr 12 01:46:51 2009] [error] [client ::1] File does not exist: /Applications/xampp/xamppfiles/htdocs/elgg/_graphics/icons/default/topbar.png, referer: http://localhost/elgg/pg/admin/plugins/

Any suggestions?

Thanks in advance,

- Guido