Debug errors for “Destination directory for file streaming does not exist or is not writable”

Your problem seems to be related with a misconfiguration of the temporary directory in PHP which is used for uploads and need to be writable when the sever downloads a WordPress, plugin or theme package.

If you can not configure it at PHP level, you can define it also in wp-config.php file:

define('WP_TEMP_DIR', ABSPATH . 'wp-content/temp/');