# Unable to browse tags using Siemens WinCC v 15

**URL:** <https://forum.inductiveautomation.com/t/unable-to-browse-tags-using-siemens-wincc-v-15/32605>\
**Category:** Ignition\
**Created:** [February 25, 2020, 9:52pm UTC](https://forum.inductiveautomation.com/t/unable-to-browse-tags-using-siemens-wincc-v-15/32605 "2020-02-25T21:52:48Z")\
**Posts on this page:** 1\
**Showing post:** 13

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [May 19, 2020, 1:31am UTC](https://forum.inductiveautomation.com/t/unable-to-browse-tags-using-siemens-wincc-v-15/32605/13 "2020-05-19T01:31:32Z")

</div>

Well, it’s complicated, but again this is a bug in this server. It’s indicating that the ByteString containing the encoded DataChangeNotification is null (length -1, FF FF FF FF in the following screenshot), which causes our decoder to move onto the next field and start decoding bogus data because the ByteString is actually present in the stream. Wireshark can see it because the way it’s written it ignores this length for built-in OPC UA types.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/2X/c/c727a1b6e80f377a06b60ed7d8c98334ccb92c36.png)

You’ll have to contact Siemens and see if they have a fix or upgrade available.

---

_[View the full topic](https://forum.inductiveautomation.com/t/unable-to-browse-tags-using-siemens-wincc-v-15/32605)._