There might be different reasons.
1. What version of Joomla is in use? Please make sure you are using latest Joomla 3.8.1 with NorrCompetition 1.7.3.
2. I see a lot of issues in the browser console. Perhaps there is a script conflict. I see all .js scripts are united in one file. Try to disable scripts compression and examine this issue again. If it will work, then you can understand what way to go.
Another tip: temporary assign another template like Protostar to examine. Perhaps the problem is in Joomla template which cause script conflict.
I use the Joomla 3.7.5 version because the last one brings me many problems I still can not solve. is it a problem?
I tried to change the template in Protostar but it still does not work: www.iriscampus.it/RicercaSviluppo/ss-att...ol2017/ss-invioopera
Can you give me directions before going mad with .js script?
Yes, there are a lot of improvements and API changes in each major version of Joomla which requires 3rd party extensions to meet these new standards. That's why incompatibility may happen if you are using an outdated version of the CMS.
Actual version of NorrCompetition (ver.1.7.3) requires Joomla 3.8.x. We can send you earlier version of NorrCompetition via e-mail if you wish. But it is recommended to keep Joomla up-to-date.
In Joonla 3.7.5 it should work fine. Can you check this topic, it could be Italian translation problem:
Maybe I was mistaken with version compatibility, so Dmitry corrected me.
Crescenzo, have you tried to disable scripts compression?
Can you give us an information what localization string has a misprint, please? We will fix the localization at Transifex.
You can get our help: Monday - Friday / 09:00 to 17:00 (GMT+2). but not limited. Our staff will be pleased to provide Premium support to every paid subscriber asap, but sometimes you should be ready to wait for our reply for up to 3 days. In case of free extensions we do the best to develop and maintain them either, but their support is not necessary.