587868ms th_a witness.cpp:168 plugin_initialize ] 10 assert_exception: Assert Exception
private_key.valid(): unable to parse private key
{}
th_a witness.cpp:112 steemit::witness_plugin::witness_plugin::plugin_initialize
587869ms th_a main.cpp:196 main ] Exiting with error:
10 assert_exception: Assert Exception
private_key.valid(): unable to parse private key
{}
th_a witness.cpp:112 steemit::witness_plugin::witness_plugin::plugin_initialize
rethrow
{}
th_a witness.cpp:168 steemit::witness_plugin::witness_plugin::plugin_initialize

What should I do?