Contract item &1 &2 cannot be selected

What causes this issue?

The item cannot be selected in the contract you have entered.

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?

Check your entries and correct them if necessary. If your entries are
correct, the current invoice contains an error. To find the correct
contract number and item number, you can display a list of all contracts
for the supplier or for the materials in the invoice. Position your
cursor on the <LS>Contract</> field, then choose the input help.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.