wordpressI’ve had some Wordprress installation problems with version 2.8.5 and with 2.8.6 when trying to install new plugins and themes via WP dashboard, as well as upgrading.

The problem:
Downloading the file works perfect and without errors but it stops when it has to unpack.
Basically, nothing happens.
I can see the zipped file on my ftp server, but this same file should be automatically unzipped and installed….which it doesn’t.

WordPress support forums has some topics on this, but people actually have errors; they do not get a black installation page after.

The fix i found that works for me:

As usual, a memory issue which can easily be fixed.
By default, most hosts limit the memory to 32MB, but the workaround in WordPress is to modify wp_settings.php on line 13 and change WP_MEMORY_LIMIT from 32 MB to 64MB.

Find the file into your WordPress root directory, back it up, make the change, save and upload.

if ( !defined(‘WP_MEMORY_LIMIT’) )
define(‘WP_MEMORY_LIMIT’, ’32M’);

change to:

if ( !defined(‘WP_MEMORY_LIMIT’) )
define(‘WP_MEMORY_LIMIT’, ’64M’);

That should fix it! After making this change, i was able to install themes and plugins without a problem whatsoever.
Try installing a new theme or plugin from your dashboard.
Hope it works for you too!