When facing the SAP error M3820 Tables TCURM and T001W inconsistent; contact your systems administrator, most likely during material creation in MM01, the issue is most likely that the plant hasn’t been assigned to the company code.
As described in the Performance Assistant, first step is to check the assignment of plants to company code.
In SPRO, find Enterprise Structure > Assignment > Logistics – General > Assign plant to company code
Once in the transaction, create a new entry
Add the values necessary – namely, the plant and the company code
A customizing request will be necessary to proceed
And that’s it ! The material creation can now proceed