If you´re getting this error it´ll be possible that you have different (old/new) configs on your switch. Compare your configs via cfgshow and check if there are any differences.

 

If there are differences enter following commands and confirm them on the switch with the oldest config:

 

cfgdisable

cfgclear

cfgsave

portdisable <Port No.>

portenable <Port No.>

 

After this your fabric should be up and running again.