I am afraid that your issue description can fit a very large number of potential issues. I would need you to specify what you have been trying to do, and what is the exact error you are receiving to be of assistance.
I can try to speed up the process by describing a common scenario and how to address it: you have uploaded the backup archive and Kickstart manually and that you have some kind of problem running Kickstart. In this case, you need to make sure that Kickstart is uploaded using the Binary transfer mode. If this is not enough please read the documentation pages on the security considerations and bypassing PHAR.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!