Error in line 124 of locking.php (Gravity Forms V. 2.5) [RESOLVED]

The Settings menu of Gravity Forms V. 2.5, the one that drops down when designing a form, is causing the white screen of death. There is an error on line 124 of locking.php. I am not a PHP coder but I know an error when I see one. Here is one sample error message that I get when selecting one of the Settings items:

Fatal error : Uncaught Error: Call to undefined function ctype_alnum() in /hermes/bosnacweb02/bosnacweb02ad/b1952/dom.lreese6248107/wp_site_1618585340/wp-content/plugins/gravityforms/includes/locking/locking.php:124

There has been a critical error on this website. Please check your site admin email inbox for instructions.

Version of WP is 5.7.1, PHP, V. 7.4.

Matthew P. Seltzer

Hi Matthew. The error is not in Gravity Forms. The issue is that your host’s PHP configuration does not include support for the ctype_alnum function. Please contact your web host and ask them to enable the PHP ctype functions for your site.

Hello, Chris,
Thank you for your extremely rapid response. I apologize for assuming that your product was at fault but I had no way to discern what was really happening. It is going to be interesting to see what’s response to this is going to be. I boggles my mind to think that they would not have the full complement of PHP libraries installed and ready for use.
I will report back after I contact them and request that they make the change to our Wordpress environment. I do have one question: will they use a command-line tool on their end to install the necessary libraries, or, is this something that can be done via cPanel? (Unfortunately, does not give users access to cPanel…otherwise, I could probably make the change, myself.)
Thank you, again,
Matthew P. Seltzer
Seltzer Software Services LLC

That will most likely need to be enabled in the PHP config via the command line. Let us know how it turns out.

I will, thanks. Have to wait until Mon. May 10.

Here’s a question for you: is this something I can do, myself, using SSH from the command line? Or would I be better off letting my web hosting company do it?

I think this is an issue the host needs to rectify at the server level. If you don’t have root, I don’t think you can do this.

I have root access, but I think my buddy is using shared hosting and not a virtual private server, which may cause problems. He may have to upgrade to a virtual private server hosting plan, because if any changes are made to the server’s PHP base installation, only he will be affected. The conversation I am going to have with promises to be an interesting one.

Hi, Chris, was able to resolve this by downgrading our version of PHP to 7.3 from 7.4. (No mention of installing the PHP common function package for 7.4 for Debian Linux. They do not open their servers to SSH connections, either.) I don’t think this will have any impact on other coding I am doing (at least, I hope not!)


Thanks for the update Matthew. Please let us know if you run into anything else.