A PHP Error was encountered

Severity: 8192

Message: strtolower(): Passing null to parameter #1 ($string) of type string is deprecated

Filename: views/sidemenu.php

Line Number: 10

Backtrace:

File: /home1/skybeg2w/public_html/svedbergopen.com/application/views/sidemenu.php
Line: 10
Function: strtolower

File: /home1/skybeg2w/public_html/svedbergopen.com/application/views/guidelines_authors_journals.php
Line: 112
Function: view

File: /home1/skybeg2w/public_html/svedbergopen.com/application/controllers/Welcome.php
Line: 211
Function: view

File: /home1/skybeg2w/public_html/svedbergopen.com/index.php
Line: 315
Function: require_once