upgrading vb3 to vb4

[chikuru]

I have lots of plugins on my vb3, and I want to upgrade to vb4..

I tried to upgrade to vb4 but it show errors on the top of the forum:

Warning: fetch_template() calls should be replaced by the vB_Template class. Template name: banner in [path]/includes/functions.php on line 4734

Warning: Cannot modify header information - headers already sent by (output started at [path]/includes/class_core.php:5615) in [path]/includes/functions.php on line 4513

How can I upgrade to vb4 without getting error?
I will no longer use the plugin if its not compatible with vb4..

Do I need to uninstall the plugins first before upgrading?

[dlewisr]

All plug ins should be disabled before upgrading so as not to conflict. Then, after upgrading, enable them one by one to see if there is an issue.