Docker slave connectivity probelem in jenkins

we have used evarga/jenkins-slave container and node created in jenkins but facing this error at launch

ERRO[0156] Error setting up exec command in container 7169d145a0da30309a11389dc498e03f1afca2c706af4e2018953ff996dd4d6a: Container 7169d145a0da30309a11389dc498e03f1afca2c706af4e2018953ff996dd4d6a is not running
ERRO[0156] Handler for POST /containers/7169d145a0da30309a11389dc498e03f1afca2c706af4e2018953ff996dd4d6a/exec returned error: Container 7169d145a0da30309a11389dc498e03f1afca2c706af4e2018953ff996dd4d6a is not running

Also we tried SSH methodology but facing this error

just before slave test-f6957ff92f8f gets launched …
executing pre-launch scripts …
[09/14/17 07:30:49] [SSH] Opening SSH connection to 192.168.99.100:32768.
[09/14/17 07:30:49] [SSH] WARNING: SSH Host Keys are not being verified. Man-in-the-middle attacks may be possible against this connection.
[09/14/17 07:30:49] [SSH] Authentication failed.
Authentication failed.
[09/14/17 07:30:49] Launch failed - cleaning up connection
[09/14/17 07:30:49] [SSH] Connection closed.