Hi Domnic,
A *** Allocation of PXA failed.
A *** Shared Memory in size 639872K not available.
A *** Stopping work process due to no
A *** shared memory available.
A *** Please decrease value of profile parameter
A *** abap/buffersize and restart the system.
A *** For further information please refer to note 307976.
If you see the above the log, the allocation of PXA failed because shared memory in size 639872K in not available.
So, you need to decrease the value of abap/buffersize and refer SAP note 307976.
Have you tried that ?
Goto RZ11 and type this parameter to check the documentation of this this patameter.
Regards,