After removing plugin, Advanced Theme Switcher via the plugin panel, I now get this error message when creating a new site as a new guest.
Warning: fopen(/home/wbtmr/public_html/wp-content/plugins/advanced-theme-switcher/advanced-theme-switcher.php) [function.fopen]: failed to open stream: No such file or directory in /home/webtamer/public_html/wp-includes/functions.php on line 3493
Warning: fread(): supplied argument is not a valid stream resource in /home/wbtmr/public_html/wp-includes/functions.php on line 3496
Warning: fclose(): supplied argument is not a valid stream resource in /home/wbtmr/public_html/wp-includes/functions.php on line 3499
And when creating a new site from the Network Admin panel, it has a fourth line as such....
Warning: Cannot modify header information - headers already sent by (output started at /home/wbtmr/public_html/wp-includes/functions.php:3493) in /home/webtamer/public_html/wp-includes/pluggable.php on line 876
Note: I tried to create this question in Plugins category but I have removed the plugin so can't select a plugin from the dropdown so moved this to the General category.
Thanks for your help.