Hi Leonid,
Thanks for reaching out although I’m sorry to hear you’re having trouble with your Total Upkeep Premium installation.
To begin troubleshooting I have some questions for you:
1.) Is this your first time installing Total Upkeep Premium on your WordPress website or did this issue occur after your initial site backup?
2.) Do you have the standard Total Upkeep plugin installed and activated as well on your site? (this is required)
3.) Does your error message provide any additional information? If so can you copy/paste it into the thread here so that we can inspect it?
You might also benefit from taking a look at this guide on installing Total Upkeep premium.
We look forward to assisting you further with this!