@issau neshiri Thank you for posting your question on Microsoft Q&A platform. Sorry for the inconvenience this must have caused you!
From the description I understand that you want to migrate your on-premises physical server to Azure and while doing so, you received an error "Protection could not be configured for the machine" not sure which operating system you are migrating from the Physical servers. Please check the pre-requisites and verify all the steps are completed before you start the process - https://video2.skills-academy.com/en-us/azure/migrate/tutorial-migrate-physical-virtual-machines
Supported and Limitations of migrating Physical Servers - https://video2.skills-academy.com/en-us/azure/migrate/migrate-support-matrix-physical-migration#physical-server-requirements https://video2.skills-academy.com/en-us/azure/site-recovery/vmware-physical-azure-support-matrix#replicated-machines
Also check this log file and upload here if possible - %ProgramData%\ASRSetupLogs\ASRUnifiedAgentInstaller.log
Make sure the installer is not blocked and running with admin permissions.
One more suggestion is to restart your Virtual Machine for the Mobility agent to start responding and communicating with your Recovery Services Vault. If the restart still does not fix it then uninstall the mobility agent from the machine, unprotect the machine and then re-protect again.
Hope this helps. Let us know how it goes!