Hi Manuel,
Probably you are trying the option “Multilanguage > Limit checking“, right?
I just sent you a modified version of the plugin where I tried to fix it for you. Please give it a try and let me know if it works better now.
Now, regarding your other question:
> Further i would like to know, if it’s possible to set the limit in the hole basket to 1 product.
There is a workaround for cases like that.
1. Enable the “Per product tag” or “Per product category” limit option.
2. Access the tag or category page and set a limit. 1
in your case.
3. Set all products with that tag or category.