"Choose Variant first" after Update

[JestaBlunt]

hi,

the customer did an update for VM 3.0.10 and after it the add-to-cart-button on products with variants disapeared and was replaced by "Choose product variant first". we are using the stockable custom-fields-plugin from breakdesign in the latest version 1.4.4.

the parent products in the plugin are all set to be orderable.

is there a workaround to change the files, so it will display the add-to-cart button?

problem is, that the customer didnt ask before updating and didnt do a backup too.

joomla: 3.4.4
VM:  3.0.10

peace,
jesta blunt