Problem installing Kaltura Plugin in ELGG 1.6.1

Hi frens,
I downloaded the kaltura plugin and enabled the plugin in my elgg site. After that based on instruction i created a partner id with Kaltura as partner id is needed in settings,. But when i put email add, password, partnerid and hit save, it gives me following error.

ailed to serialize server result

Exception Object
(
[message:protected] => failed to serialize server result

[string:private] => exception 'Exception' with message 'failed to serialize server result
' in /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/KalturaClientBase.php:125
Stack trace:
#0 /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/KalturaClient.php(4232): KalturaClientBase->doQueue()
#1 /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/kaltura_helpers.php(172): KalturaPartnerService->getSecrets('98842', 'ashishshr85@hot...', 'mk7KJvRC')
#2 /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/kaltura_helpers.php(97): KalturaModel->getSecrets('98842', 'ashishshr85@hot...', 'mk7KJvRC')
#3 /opt/ibm/vhosts/social2/mod/kaltura_video/start.php(104): kaltura_partner_processing(Array)
#4 /opt/ibm/vhosts/social2/engine/lib/elgglib.php(1511): kaltura_video_init('init', 'system', NULL)
#5 /opt/ibm/vhosts/social2/engine/lib/elgglib.php(1578): events('init', 'system', '', NULL, true, NULL)
#6 /opt/ibm/vhosts/social2/engine/start.php(192): trigger_elgg_event('init', 'system')
#7 /opt/ibm/vhosts/social2/engine/handlers/action_handler.php(17): require_once('/opt/ibm/vhosts...')
#8 {main}
[code:protected] => 0
[file:protected] => /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/KalturaClientBase.php
[line:protected] => 125
[trace:private] => Array
(
[0] => Array
(
[file] => /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/KalturaClient.php
[line] => 4232
[function] => doQueue
[class] => KalturaClientBase
[type] => ->
[args] => Array
(
)

)

[1] => Array
(
[file] => /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/kaltura_helpers.php

I have curl library enabled in my php.ini settings.Please help
[line] => 172
[function] => getSecrets
[class] => KalturaPartnerService
[type] => ->
[args] => Array
(
[0] => 98842
[1] => ashishshr85@hotmail.com
[2] => mk7KJvRC
)

)

[2] => Array
(
[file] => /opt/ibm/vhosts/social2/mod/kaltura_video/kaltura/api_client/kaltura_helpers.php
[line] => 97
[function] => getSecrets
[class] => KalturaModel
[type] => ->
[args] => Array
(
[0] => 98842
[1] => ashishshr85@hotmail.com
[2] => mk7KJvRC
)

)

[3] => Array
(
[file] => /opt/ibm/vhosts/social2/mod/kaltura_video/start.php
[line] => 104
[function] => kaltura_partner_processing
[args] => Array
(
[0] => Array
(
[partner_id] => 98842
[email] => ashishshr85@hotmail.com
[password] => mk7KJvRC
)

)

)

[4] => Array
(
[file] => /opt/ibm/vhosts/social2/engine/lib/elgglib.php
[line] => 1511
[function] => kaltura_video_init
[args] => Array
(
[0] => init
[1] => system
[2] =>
)

)

[5] => Array
(
[file] => /opt/ibm/vhosts/social2/engine/lib/elgglib.php
[line] => 1578
[function] => events
[args] => Array
(
[0] => init
[1] => system
[2] =>
[3] =>
[4] => 1
[5] =>
)

)

[6] => Array
(
[file] => /opt/ibm/vhosts/social2/engine/start.php
[line] => 192
[function] => trigger_elgg_event
[args] => Array
(
[0] => init
[1] => system
)

)

[7] => Array
(
[file] => /opt/ibm/vhosts/social2/engine/handlers/action_handler.php
[line] => 17
[args] => Array
(
[0] => /opt/ibm/vhosts/social2/engine/start.php
)

[function] => require_once
)

)

)