Storage bin is assigned as a fixed storage bin; cannot be deleted

What causes this issue?

Storage bins cannot be deleted if they are assigned as fixed storage
bins in the Warehouse Management View 2 in the material master.

How to fix this error?

Check if the storage bin is really meant to be deleted. If it is, remove
its assignment as a fixed storage bin in the material master. Use
transaction LX29 to check which material numbers have the storage bin
assigned as a fixed storage bin.

Error message extract from SAP system. Copyright SAP SE.