Hi Fabrizio,
you can refer to these guides:
- https://my.webratio.com/learn/learningobject/analyze-error-logs-v-72
- https://my.webratio.com/learn/learningobject/using-visual-debug-v-72
- https://my.webratio.com/learn/learningobject/how-to-debug-the-code-of-a-custom-unit-inside-the-web-application
I hope this will help you.