My system is windows

There are two versions of ADB running in the system. It’s useless to execute ADB kill server. You have to deal with it yourself

both versions are installed by myself. Then remove the redundant version. I’m not this error. I won’t describe the operation in detail

other programs execute ADB * – server.exe, and occupy port 5037

netstat -ano | findstr “5037”

# > netstat -ano | findstr "5037"
TCP    127.0.0.1:5037         0.0.0.0:0              LISTENING       6312

Find the program with PID 6312

# > TASKLIST | findstr "6312"
PPAdbServer.exe               6312 Console                    1      7,104 K

This ppadbserver.exe occupies the port. Kill this to taskkill/F/im ppadbserver.exe , and then execute abd start server

# > adb start-server
* daemon not running; starting now at tcp:5037
* daemon started successfully

OK, OK