Apologies for the trouble everyone. I’m aware that some users are having issues upgrading from Webcomic 3, but I haven’t determined what exactly is causing the issue just yet. A few things that might help:
Downgrading
If you’re upgrade fails but you still have access to the Upgrade Webcomic page, the safest way to downgrade is to click Not Interested button on that page to uninstall Webcomic 4 and then reinstall Webcomic 3 (which can be downloaded from here or here). This should retain your Webcomic 3 settings properly.
Webcomic 3 Settings MIssing
Missing settings are the cause of most issues if you’ve attempted to upgrade and then downgraded back to Webcomic 3 (including the inability to properly set a default collection). The process described above should maintain these settings (it’s also shouldn’t fail, of course, and we know how that’s going).
If it doesn’t retain your Webcomic 3 settings or your settings were lost for some other reason the easiest way to restore them is from a backup. You shouldn’t need to do a full-site restore; only Webcomic 3’s settings should be missing (even when it fails, Webcomic 4’s upgrade process shouldn’t delete any of your data except for these “old” settings). Webcomic’s settings can be found in the wp_options table of the WordPress database with an option_name of webcomic_options.
If you your settings didn’t transfer correctly and you don’t have a backup you can try checking that same database table for an option named webcomic_legacy. This is a temporary option Webcomic 4 uses to store your old settings for use during the upgrade. If it exists (and isn’t empty) you should be able to copy and past the value from this option into the correct webcomic_options setting.
If all else fails, simply updating your settings from the Webcomic > Settings administrative page will rebuild the settings, but certain features may or may not work.
404 Error’s after a Downgrade
If everything looks correct but you’re getting 404 errors on webcomic-related pages your pretty permalink settings may need to be flushed. This can be done by changing the Permalink setting and saving (then switching back and saving again) or by adding the following function to your theme functions.php file:
flush_rewrite_rules( true );
and visiting any page on your site. If you try using flush_rewrite_rules() you should remove it after you’ve visited a page or two; it’s not meant to be run on every single page load (which is what happens when you add it to your theme functions.php file).
Apologies again for the trouble. I’m currently at a day-job-releated conference, and almost never drop in at WordPress.org besides. I’ve set it so that I’ll be notified of future posts to this thread, but I’d recommend posting on the Webcomic Google Group for further assistance (many of these issues have been discussed there already).
