How to Fix the “Nothing to Repeat” Error in Shack Forms Pro Forms

In some use cases, you may see the following error when you open a front-end page with a Shack Forms Pro form:

Invalid regular expression: Nothing to repeat

the nothing to repeat

Here’s the easy fix.

In your Joomla dashboard, go to Components > Shack Forms Pro > Modules.
This will bring you to the "Shack Forms: Modules" screen. Open the module that shows the error.
On the Module tab, go to the Email field.
In the Validation (Regular Expression) field, delete the validation code.

validation code to repeat

Click Save & Close.
Reload your page with the form. The “Nothing to repeat” message should now be gone.

Shack Forms Documentation