psalm: PHP Fatal error: Uncaught UnexpectedValueException in Version 3.5.2

hey, I updated to version 3.5.2 today and got this exception while executing psalm.

PHP Fatal error:  Uncaught UnexpectedValueException: There should be types here in /vendor/vimeo/psalm/src/Psalm/Internal/Type/TypeCombination.php:461
Stack trace:
#0 /vendor/vimeo/psalm/src/Psalm/Type.php(1438): Psalm\Internal\Type\TypeCombination::combineTypes(Array, NULL, false, true, 500)
#1 /vendor/vimeo/psalm/src/Psalm/Type/Atomic/ObjectLike.php(224): Psalm\Type::combineUnionTypes(Object(Psalm\Type\Union), Object(Psalm\Type\Union))
#2 /vendor/vimeo/psalm/src/Psalm/Type/Atomic/GenericTrait.php(184): Psalm\Type\Atomic\ObjectLike->getGenericValueType()
#3 /vendor/vimeo/psalm/src/Psalm/Type/Union.php(1388): Psalm\Type\Atomic\TArray->replaceTemplateTypesWithStandins(Array, Array, Object(Psalm\Codebase), Object(Psalm\Type\Atomic\ObjectLike), true, in /vendor/vimeo/psalm/src/Psalm/Internal/Type/TypeCombination.php on line 461

Unfortunately I could not find out, on which file the operations fails. If you could give me a hint, I could investigate further