Help with mysql error during sales invoice posting

1

Please can someone help with this? I have an installation in my shop, on submitting invoice it hangs on submitting and hitting f12 shows error 500 in the chrome console with a strange json error. At first I thought it was mysql packet setting but I observed I had raised max_allowed_packet to around 128M already, I also did set global max_allowed_packet to something very large. Can somneone look at the trace as shown in the attached and tell me what could be wrong?

Thanks in anticipation

pos_error2
pos_error21351×596 64.9 KB

pos_error
pos_error1365×593 35.9 KB

2

Seems mysql went down! please check mysql error logs

3

Thanks @saurabh6790

I will check again, I have tried so many things, its such a small database so I wonder why this has happened, its barely 3 days up and just a few items.