CSV Import is not working

Hello there, first of all: compliments for the plugin, it is working very smooth!

We are trying now to import a CSV file with the import/export function in the plugin. The plugin is reading the file well (we are seeing the first 5 rows of the CSV file) and we are able to select the columns where we want to put the data in, but when we are choosing for import we are ending in a screen with the text:

Links imported:

But unfortunately, no single link is imported. Can someone please help me out?