does some one know what this mean and what i can do about it.
 


[2017-09-30 19:50:11.133] API bind to port 4028 failed - trying again in 30sec
 [2017-09-30 19:50:41.134] API bind to port 4028 failed - trying again in 30sec
 [2017-09-30 19:51:11.135] API bind to port 4028 failed - trying again in 30sec
 [2017-09-30 19:51:22.860] Stratum from pool 0 detected new block at height 487715
 [2017-09-30 19:51:41.135] API bind to port 4028 failed (Address already in use) - API will not be available
 [2017-09-30 20:00:34.131] Stratum from pool 0 detected new block at height 487716
 [2017-09-30 20:15:05.828] Stratum from pool 0 detected new block at height 487717
 [2017-09-30 20:15:05.829] Failed to create restart thread errno=12 in cgminer.c restart_threads():5046