I deactivated and deleted the version I was using and installed the latest version, 2.8.1, and still have the problem.
This is only an issue in 2.8.1. That version introduced some improvements to the custom dropdown field so that comas could be used in the dropdown values. This involved the use of str_getcsv, which requires PHP 5.3 or higher. str_getcsv is not used in 2.8.0.
I am rethinking the use of str_getcsv as it really should not have been used, since WP currently requires only PHP 5.2.4. So I will patch this in 2.8.2 (and possibly will release a separate patch earlier). In the meantime, you have some possible options:
- Roll back to 2.8.0. I don't recommend this as 2.8.1 included security updates. (You could rollback, install your dropdown fields, then upgrade.)
- Upgrade your PHP version to 5.3+ (recommended)
- Install the Pear PHP_Compat package, which allows earlier PHP versions certain newer functions (including str_getcsv). This is also not recommended as this package does have some bugs.
- Wait for the patch/upgrade when I fix this.