1. does your language was already in the list?
2. if not, I guess you Add a new language...
3. if I'm right, you have to click on Rescan, a box will appear, then click on scan.
4. Once it's done, click on modify, you should see all the terms to translate... and you will have to translate them all....
2b. if your language was already there, then proceed to step 3 and 4; none, some, a lot, almost all or all terms will be already translated.
If no files appears... then I don't know what to tell you as it is what I done for another Woocommerce extension and it worked...