12 files declare their use of UnexpectedValueException in Zircon Profile 8

ContentEntityNormalizer.php in core/modules/hal/src/Normalizer/ContentEntityNormalizer.php

Contains \Drupal\hal\Normalizer\ContentEntityNormalizer.

DecoderInterface.php in vendor/symfony/serializer/Encoder/DecoderInterface.php

DenormalizeTest.php in core/modules/hal/src/Tests/DenormalizeTest.php

Contains \Drupal\hal\Tests\DenormalizeTest.

EncoderInterface.php in vendor/symfony/serializer/Encoder/EncoderInterface.php

EntityNormalizer.php in core/modules/serialization/src/Normalizer/EntityNormalizer.php

Contains \Drupal\serialization\Normalizer\EntityNormalizer.

JsonDecode.php in vendor/symfony/serializer/Encoder/JsonDecode.php

JsonEncode.php in vendor/symfony/serializer/Encoder/JsonEncode.php

RequestHandler.php in core/modules/rest/src/RequestHandler.php

Contains \Drupal\rest\RequestHandler.

SerializationTest.php in core/modules/serialization/src/Tests/SerializationTest.php

Contains \Drupal\serialization\Tests\SerializationTest.

Serializer.php in vendor/symfony/serializer/Serializer.php

XmlEncoder.php in vendor/symfony/serializer/Encoder/XmlEncoder.php

XmlEncoderTest.php in vendor/symfony/serializer/Tests/Encoder/XmlEncoderTest.php