MARA locked by another user

What causes this issue?

You have set the "Lock MARA" indicator. Another user is currently
processing materials and has therefore locked table MARA.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Carry out this function later.
Note
You have the possibility of resetting the indicator. However, do not do
this unless you are sure that no other user is processing a material
from the specified area.

Error message extract from SAP system. Copyright SAP SE.