Question: Need to count in C# app, minutes in SLA to show in format : 

```
N working days, N working hours, N working minutes

```

current code show up only hours:minutes format:

```
TimeSpan spWorkMin = TimeSpan.FromMinutes(12534);
string workHours = string.Format("{0}:{1:00}", (int)spWorkMin.TotalHours, spWorkMin.Minutes);
Console.WriteLine(workHours);

```

Answer: 
This could be due to module being not installed properly or the installed Python package is an older version.
Check if the opcua module is installed using

```
pip list

```

If the problem persists, then try updating the Python package (Python version > 3.4), else try using pip3 instead of pip.

Since the python-opcua library is in maintenance mode, you can try out the examples available in opcua-asyncio which is the fork of python-opcua: <https://github.com/FreeOpcUa/opcua-asyncio/tree/master/examples>

You can refer to the documentation available here: <https://opcua-asyncio.readthedocs.io/en/latest/>

You can also try out these open source OPC UA implementations that you might find interesting:

* open62541 – <https://open62541.org/certified-sdk.html> – C stack |
Mozilla License | Embedded ready | TSN ready
* NodeOPCUA – <https://node-opcua.github.io/> – NodeJS | MIT License |
Cloud ready
* UA .NET stack – <https://github.com/OPCFoundation/UA-.NETStandard> –
RCL License for corporate members of OPC Foundation & GPL 2.0 for
others | Standard profile | Web oriented implementation

If you are looking for more hands-on information (it uses another open source stack) , you can also check out these resources:

* Free documentation: You can look at the open source documentation
page: <https://open62541.org/doc/current/>
* Paid online course: Practical introduction to OPC UA – code
walk-through and examples in this course use the open62541 stack:
<https://opcfoundation.org/products/view/practical-introduction-to-opc-ua-part-i>
Looks like you didn't install opcua correctly.

Try to use `pip list` to check is it installed.

You can get examples from <https://github.com/FreeOpcUa/python-opcua>, and go to examples folder.

```
$ python server-minimal.py    

```

Open another terminal

```
$ python client-minimal.py

Objects node is:  Node(TwoByteNodeId(i=84))
Children of root are:  [Node(NumericNodeId(i=85)), Node(NumericNodeId(i=86)), 
Node(NumericNodeId(i=87))]
myvar is:  Node(NumericNodeId(ns=2;i=2))
myobj is:  Node(NumericNodeId(ns=2;i=1))

```

crypthography is just for security, it's not necessary to install.

If crypthography is not installed, you will get a message,

```
cryptography is not installed, use of crypto disabled

```