“Something went wrong…” Variable products

I just purchased the variable product import add-on, but it is not working.

I installed the add-on successfully and I can upload the headers without problems, but when I try to upload a .csv file it pop up a Message Box: “Something went wrong. We could not make a connection with the server.”

I saw this link: https://allaerd.org/ajax-error-import/ , but I have uploaded the simple products without problems, so I think is not because of the server. I tried uploading first the “variation_master” and then the “product_variation”. When I upload only “variation_master” products there is no problem, but when I try to upload “product_variation” products, the plugin doesn’t work.

I created the attributes in the Woocommerce Product section before. This is the log file when I tried to upload only variation products.

— Skipping the first line
New product

—–> Row

I have my wordpress page in a local server using MAMP.

Thank you in advance.