Hey okay, i have exported private key file of multibit (multibit.key) but how can no i import this file into Bitcoin core? Bitcoin core only accepts key adress trough console not files to be imported.
Open your multibit classic key file in notepad, copy the private key, then import it into core using the console. In the quoted example of the contents of a key file the private key is shown in red.
# KEEP YOUR PRIVATE KEYS SAFE !
# Anyone who can read this file can spend your bitcoin.
#
# Format:
# <Base58 encoded private key>[<whitespace>[<key createdAt>]]
#
# The Base58 encoded private keys are the same format as
# produced by the Satoshi client/ sipa dumpprivkey utility.
#
# Key createdAt is in UTC format as specified by ISO 8601
# e.g: 2011-12-31T16:42:00Z . The century, 'T' and 'Z' are mandatory
#
KwUVsx4nd4UTHUtNTPnLEEqapCFvNiBrVASBZPa1ZvStQbUD87VK 2017-03-26T01:36:45Z
# End of private keys