Hello,

As you are using “Pimwick Gift Card” plugin, You also contain some other plugins and it is possible that some other plugin conflict with the pimwick gift card plugin, if you have recently added some new plugins or added some custom code, then deactivate those plugins, undo the code and then check back. Or you can also deactivate all other plugins except of pimwick plugin then activate plugins one by one and you will find the one which cause this issue.

Best Regards.