First, there are no phone numbers for Magix Support; as a first stage, support is offered in this forum by fellow-users. If we are unable to help, Magix has a ticket-based Support system towards which we can guide you.
Unfortunately, your first post here is rather lacking in details but I am going to guess that you have Magix PC Check and Tuning (or similar), it previously worked but now no longer does. Is that correct?
If so, when did you purchase the app? I believe the initial purchase is for twelve months of use, measured from the date of purchase. Towards the end of that time you should have received at least one email from Magix advising that you needed to renew the Update Service for the product of you wished to continue benefitting from it. Did you receive that email? If not, you need to email infoservice@magix.net and ask that they resend it.
By the way, you say no emails answered. To which address did you send them?
OTOH, if you are not asking about that specific software please give us a lot more details about which product you have and about your computer (this post will show the info that is vital for us!). Please put this into your Signature then we don't need to request it every time you post a question, thank you.
Are you getting any error message when starting PC check and Tuning 2022 ?
Does the program start if you temporarily disable your Antivirus program? These have been known to cause issue with programs such as PC check and Tuning - if the program runs then you need to add an exception to your Antivirus program.
If the above does not work then raise a support ticket - see this Support article on how to navigate the support system.
The serial number you provided is not correct. please make sure you entered the serial number correctly. Get help here. I click on the link and it sends me to Magix support new request.
If you are certain you are entering the full serial key correctly (a common mistake is to put in 0 (zero) instead of O (letter O), or vice versa), the best method is always to copy and paste, you need to follow the link that @johnebaker gave you in his second reply to you and create a Support Ticket. We are all fellow-users and have no means of checking whether your serial key is correct, or otherwise.
You were previously advised to NOT post confidential data like order numbers to this public forum. So why have you not followed that advice in your latest post?
The order number has now been removed!
If you are NOT seeing any of the "errors" or error codes which @johnebaker listed then...
Please create a Support ticket. Please click here to go to the page which explains exactly what you must do. Always ensure you click on the option to Ask Support wherever this is offered, often at the foot of any page.
No-one who posts here can give you any further help, sorry.