Dear Pennylane-Team,

I have a question regarding a code-snippit I wrote about > year ago in pennylane 0.25.1.

I updated now my pennylane version to 0.35.1 and run into a problem that I don’t understand.

In the following I provide a minimal example where I try to implement my own template.

In this minimal example, the template should solely realize an RY-rotation to encode my input.

When I run the code I get the following error.

When using “default.qubit”:

DeviceError: Operator minimalExample(array([0.78539816]), wires=[0]) not supported on default.qubit and does not provide a decomposition.

When using “default.qubit.torch”:

DeviceError: Gate minimalExample not supported on device default.qubit.torch

I checked with this example ( How to add custom gates and templates to PennyLane | PennyLane Blog) and can’t find the error.

Here is the code:

- I define the minimal Template Example

```
import numpy as np
import torch
import pennylane as qml
from pennylane.operation import Operation, AnyWires
class minimalExample(Operation):
r"""
Template of minimal example
"""
num_wires = AnyWires
par_domain = "A"
def __init__(self, features, wires, alpha="Y", varphi="arccos",
beta=1.0, id=None):
super().__init__(features, wires=wires, id=id)
@property
def num_params(self):
return 1
def expand(self):
r"""
Implements the encoding of the input parameters.
"""
num_weights = qml.math.shape(features)[0]
with qml.tape.QuantumTape() as tape:
for i in range(num_weights):
qml.RY(features[0], wires=self.wires[i])
return tape
```

- I tried to initiate the input values as numpy.array or torch.tensor. When using torch.tensor I used it with default.qubit.torch

```
inputNumpy = np.array([np.pi / 4])
#inputTorch = torch.tensor([np.pi / 4])
nqubit = 1
dev = qml.device("default.qubit", wires=nqubit)
#dev = qml.device("default.qubit.torch", wires=nqubit)
@qml.qnode(dev)
#@qml.qnode(dev, interface='torch', diff_method='backprop')
def qcFkt(inputs, wires):
""" QC function that performs encoding via the Templates"""
minimalExample(inputs, range(wires))
return [qml.expval(qml.PauliZ(i)) for i in range(wires)]
```

Calling this circuit gives me the described errors.

```
qcFkt(inputTorch, nqubit)
```

Thank you very much and best regards,

Pia