Newbie with a problem

Hello, Not only am I a Newbie but I am not Tech Savy. I hope someone can help me out.
I have a synology NAS and I am running websites and Piwik on it.

Under settings and and security I get this message (4 times in a row) on the top window before the tabs.
Can anyone help me solve this error? (Here is the challenge, I need the answer in simple terms so that I can understand.)
Thanks in advance.

There is an error. Please report the message (Piwik 1.9.1) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: exec(): PHP exec disable. in /volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/Test/Test.php on line 514

Backtrace -->

#0 Piwik_ErrorHandler(…) called at [:]
#1 exec(…) called at [/volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/Test/Test.php:514]
#2 PhpSecInfo_Test->getUnixId(…) called at [/volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/Test/Core/uid.php:57]
#3 PhpSecInfo_Test_Core_Uid->_retrieveCurrentValue(…) called at [/volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/Test/Test.php:118]
#4 PhpSecInfo_Test->PhpSecInfo_Test(…) called at [/volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/PhpSecInfo.php:276]
#5 PhpSecInfo->runTests(…) called at [/volume1/web/piwik/plugins/SecurityInfo/PhpSecInfo/PhpSecInfo.php:476]
#6 PhpSecInfo->loadAndRun(…) called at [/volume1/web/piwik/plugins/SecurityInfo/Controller.php:28]
#7 Piwik_SecurityInfo_Controller->index(…) called at [:]
#8 call_user_func_array(…) called at [/volume1/web/piwik/core/FrontController.php:138]
#9 Piwik_FrontController->dispatch(…) called at [/volume1/web/piwik/index.php:53]

don’t worry about this error as it’s not a problem for you, but we could fix it to prevent error - please create aticket in with full error ?