Hi vannifromtalamone,
Thanks for using the Apple Support Communities! I'm sorry to hear you are having these issues with your Mac. I'm sure we can help you figure out what is going on, but we may need a bit more information and detail about what exactly you are seeing. Any additional info you can provide may help us help you:
1. Is this the exact, entire text of the error message? Is it originally in English, or is it being translated?
2. When did this issue start, or when did you first notice it? Did anything change around that time (any new settings, updates, applications, etc)?
3. Are you currently downloading or installing anything from the Mac App Store or otherwise?
Thanks!