I updated from version 1.2.1, and am getting the error "Invalid action for form creation." when I go to upload. The update.php produced no errors when I ran it. What should I do?
I updated to stable version 1.3.1
Make sure all files were replaced with the new versions. I'd recommend deleting all the php files except config.inc.php and uploading them fresh.
Be my guinea pig for a new script I just finished: it checks if you have really replaced all necessary files when upgrading. Get the file from the attachment, unzip it and upload it to coppermine's root folder. Then browse it (by entering http://yoursite.tld/your_coppermine_folder/versioncheck.php into your browser's address bar). All entries in red that show up mean you haven't replaced the files as needed. Please report back.
GauGau