6 files declare their use of ReferenceNotFoundException in Feeds 8.3

ConfigEntityReference.php in src/Feeds/Target/ConfigEntityReference.php

ConfigEntityReferenceTest.php in tests/src/Unit/Feeds/Target/ConfigEntityReferenceTest.php

EntityReference.php in src/Feeds/Target/EntityReference.php

EntityReferenceTest.php in tests/src/Unit/Feeds/Target/EntityReferenceTest.php

UserRole.php in src/Feeds/Target/UserRole.php

UserRoleTest.php in tests/src/Unit/Feeds/Target/UserRoleTest.php