Warning: Trying to access array offset on value of type null in C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-content\themes\manufacturer\header.php on line 241

Fatal error: Uncaught Error: Call to undefined function is_shop() in C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-content\themes\manufacturer\header.php:285 Stack trace: #0 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-includes\template.php(810): require_once() #1 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-includes\template.php(745): load_template() #2 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-includes\general-template.php(48): locate_template() #3 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-content\themes\manufacturer\page.php(14): get_header() #4 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-includes\template-loader.php(106): include('...') #5 C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-blog-header.php(19): require_once('...') #6 C:\inetpub\vhosts\correctbiz.com\httpdocs\index.php(17): require('...') #7 {main} thrown in C:\inetpub\vhosts\correctbiz.com\httpdocs\wp-content\themes\manufacturer\header.php on line 285