An error occurred in script in footer.html' on line 17: Undefined index: user_level

[collisiondetection]

Why am I getting this error?

An error occurred in script 'C:\wamp64\www\TEST\html\includes\footer.html' on line 17: Undefined index: user_level Date/Time: 4-11-2018 17:59:52 Array ( [_GET] => Array ( )

[_POST] => Array
    (
    )

[_COOKIE] => Array
    (
        [JSESSIONID_54e4bf14] => node0k094xie7mjd2lxkiagjx401e1.node0
        [screenResolution] => 1366x768
        [PHPSESSID] => 7ka4rn6emk2lm3mj87gujkak0r
    )

[_SERVER] => Array
    (
        [HTTP_HOST] => localhost
        [HTTP_CONNECTION] => keep-alive
        [HTTP_UPGRADE_INSECURE_REQUESTS] => 1
        [HTTP_USER_AGENT] => Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36
        [HTTP_ACCEPT] => text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
        [HTTP_DNT] => 1
        [HTTP_REFERER] => http://localhost/TEST/
        [HTTP_ACCEPT_ENCODING] => gzip, deflate, br
        [HTTP_ACCEPT_LANGUAGE] => en-US,en;q=0.9
        [HTTP_COOKIE] => JSESSIONID.54e4bf14=node0k094xie7mjd2lxkiagjx401e1.node0; screenResolution=1366x768; PHPSESSID=7ka4rn6emk2lm3mj87gujkak0r
        [PATH] => C:\Program Files\IBM\SPSS\ModelerSubscription\1.0\ext\bin\spss.TMWBServer\bin;C:\Ruby25-x64\bin;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\PuTTY\;C:\Program Files\Amazon\AWSCLI\;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\xampp\php;C:\ProgramData\ComposerSetup\bin;C:\Program Files\Git\cmd;C:\wamp64\bin\php\php5.6.31;
        [SystemRoot] => C:\Windows
        [COMSPEC] => C:\Windows\system32\cmd.exe
        [PATHEXT] => .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.RB;.RBW
        [WINDIR] => C:\Windows
        [SERVER_SIGNATURE] => 

Apache/2.4.27 (Win64) PHP/7.1.9 Server at localhost Port 80

        [SERVER_SOFTWARE] => Apache/2.4.27 (Win64) PHP/7.1.9
        [SERVER_NAME] => localhost
        [SERVER_ADDR] => ::1
        [SERVER_PORT] => 80
        [REMOTE_ADDR] => ::1
        [DOCUMENT_ROOT] => C:/wamp64/www
        [REQUEST_SCHEME] => http
        [CONTEXT_PREFIX] => 
        [CONTEXT_DOCUMENT_ROOT] => C:/wamp64/www
        [SERVER_ADMIN] => [email protected]
        [SCRIPT_FILENAME] => C:/wamp64/www/TEST/html/index.php
        [REMOTE_PORT] => 62716
        [GATEWAY_INTERFACE] => CGI/1.1
        [SERVER_PROTOCOL] => HTTP/1.1
        [REQUEST_METHOD] => GET
        [QUERY_STRING] => 
        [REQUEST_URI] => /TEST/html/
        [SCRIPT_NAME] => /TEST/html/index.php
        [PHP_SELF] => /TEST/html/index.php
        [REQUEST_TIME_FLOAT] => 1523483992.611
        [REQUEST_TIME] => 1523483992
    )

[_ENV] => Array
    (
    )

[_REQUEST] => Array
    (
    )

[_FILES] => Array
    (
    )

[page_title] => Welcome to this Site!
[_SESSION] => Array
    (
        [user_id] => 1
        [user_tz] => America/New_York
    )

)

#0 my_error_handler(8, Undefined index: user_level, C:\wamp64\www\TEST\html\includes\footer.html, 17, Array ([_GET] => Array (),[_POST] => Array (),[_COOKIE] => Array ([JSESSIONID_54e4bf14] => node0k094xie7mjd2lxkiagjx401e1.node0,[screenResolution] => 1366x768,[PHPSESSID] => 7ka4rn6emk2lm3mj87gujkak0r),[_SERVER] => Array ([HTTP_HOST] => localhost,[HTTP_CONNECTION] => keep-alive,[HTTP_UPGRADE_INSECURE_REQUESTS] => 1,[HTTP_USER_AGENT] => Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36,[HTTP_ACCEPT] => text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,/;q=0.8,[HTTP_DNT] => 1,[HTTP_REFERER] => http://localhost/TEST/,[HTTP_ACCEPT_ENCODING] => gzip, deflate, br,[HTTP_ACCEPT_LANGUAGE] => en-US,en;q=0.9,[HTTP_COOKIE] => JSESSIONID.54e4bf14=node0k094xie7mjd2lxkiagjx401e1.node0; screenResolution=1366x768; PHPSESSID=7ka4rn6emk2lm3mj87gujkak0r,[PATH] => C:\Program Files\IBM\SPSS\ModelerSubscription\1.0\ext\bin\spss.TMWBServer\bin;C:\Ruby25-x64\bin;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client;C:\Program Files\Intel\iCLS Client;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Program Files\PuTTY;C:\Program Files\Amazon\AWSCLI;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\WiFi\bin;C:\Program Files\Common Files\Intel\WirelessCommon;C:\xampp\php;C:\ProgramData\ComposerSetup\bin;C:\Program Files\Git\cmd;C:\wamp64\bin\php\php5.6.31;,[SystemRoot] => C:\Windows,[COMSPEC] => C:\Windows\system32\cmd.exe,[PATHEXT] => .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.RB;.RBW,[WINDIR] => C:\Windows,[SERVER_SIGNATURE] => Apache/2.4.27 (Win64) PHP/7.1.9 Server at localhost Port 80

,[SERVER_SOFTWARE] => Apache/2.4.27 (Win64) PHP/7.1.9,[SERVER_NAME] => localhost,[SERVER_ADDR] => ::1,[SERVER_PORT] => 80,[REMOTE_ADDR] => ::1,[DOCUMENT_ROOT] => C:/wamp64/www,[REQUEST_SCHEME] => http,[CONTEXT_PREFIX] => ,[CONTEXT_DOCUMENT_ROOT] => C:/wamp64/www,[SERVER_ADMIN] => [email protected],[SCRIPT_FILENAME] => C:/wamp64/www/TEST/html/index.php,[REMOTE_PORT] => 62716,[GATEWAY_INTERFACE] => CGI/1.1,[SERVER_PROTOCOL] => HTTP/1.1,[REQUEST_METHOD] => GET,[QUERY_STRING] => ,[REQUEST_URI] => /TEST/html/,[SCRIPT_NAME] => /TEST/html/index.php,[PHP_SELF] => /TEST/html/index.php,[REQUEST_TIME_FLOAT] => 1523483992.611,[REQUEST_TIME] => 1523483992),[_ENV] => Array (),[_REQUEST] => Array (),[_FILES] => Array (),[page_title] => Welcome to this Site!,[_SESSION] => Array ([user_id] => 1,[user_tz] => America/New_York))) called at [C:\wamp64\www\TEST\html\includes\footer.html:17] #1 include(C:\wamp64\www\TEST\html\includes\footer.html) called at [C:\wamp64\www\TEST\html\index.php:27] Some Page Another Page