No, I am sorry, we cannot have a call. I am not an employee of NGSoftware. I am a forum moderator, another user.
Support occurs on this forum. As I said before, you need to furnish more information, not just ask for help blindly. No one can give help without information.
Let’s start with your edition. Are you using the cloud edition? If so, all you need to do is log back into your account.
Or are you using the desktop edition, as seems more likely? If so, you were entirely responsible for making any backups of your business data file. No one else has any backup. But your data was never in the program. It is a data file in your application data folder. See this Guide for a discussion: https://www.manager.io/guides/8394.
I don’t know why your OS upgrade seems to have broken the link to your data file. The solution is to locate the data and import the business according to instructions here: https://www.manager.io/guides/8890. But understand one thing clearly: the Manager program did nothing to delete your data. No Manager update ever does. If your data is missing, it is because of something you did during the OS upgrade. Possibly, you made a choice to archive data somewhere. Possibly you erased or reformatted our drive first. Possibly, your data is sitting right where the program expects it to be, but needs to be imported. Only a complete description of the actions you took will help anyone guide you in trying to locate your data, if it can be recovered.