Cannot assign a device for operation encoder/down1/downs_0/conv1/weight/Initializer/random_uniform/RandomUniform: Could not satisfy explicit device specification '' because the node {{colocation_node encoder/down1/downs_0/conv1/weight/Initializer/random_uniform/RandomUniform}} was colocated with a group of nodes that required incompatible device '/device:GPU:0'. All available devices [/job:localhost/replica:0/task:0/device:CPU:0, /job:localhost/replica:0/task:0/device:GPU:0]. Colocation Debug Info: Colocation group had the following types and supported devices: Root Member(assigned_device_name_index_=-1 requested_device_name_='/device:GPU:0' assigned_device_name_='' resource_device_name_='/device:GPU:0' supported_device_types_=[CPU] possible_devices_=[] Identity: GPU CPU Mul: GPU CPU AddV2: GPU CPU Sub: GPU CPU RandomUniform: GPU CPU Assign: CPU VariableV2: GPU CPU Const: GPU CPU