# \[BUG\] UDT Instance non-existent tag reading "Error\_Configuration" instead of "Bad\_NotFound"

**URL:** <https://forum.inductiveautomation.com/t/bug-udt-instance-non-existent-tag-reading-error-configuration-instead-of-bad-notfound/104623>\
**Category:** Ignition\
**Created:** [April 3, 2025, 2:11am UTC](https://forum.inductiveautomation.com/t/bug-udt-instance-non-existent-tag-reading-error-configuration-instead-of-bad-notfound/104623 "2025-04-03T02:11:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [April 3, 2025, 2:11am UTC](https://forum.inductiveautomation.com/t/bug-udt-instance-non-existent-tag-reading-error-configuration-instead-of-bad-notfound/104623/1 "2025-04-03T02:11:35Z")

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v8.1.47

Not sure there's much I can provide that will help to provide backups or logs to diagnose the cause for this one, but it's more a what-to-do if it happens to someone else.

I have 2x UDT definitions for a valve, one has open/close commands and the other doesn't (control valve), however reading the control valve's non-existent open or close tags returned "Error\_Configuration" instead of "Bad\_NotFound" which was messing with [`isAvailable`](https://forum.inductiveautomation.com/t/ignition-extensions-convenience-utilities-for-advanced-users/64615)'s conditions and returning `true` instead of `false`.

To fix it, I had to add the two non-existent tags to the definition and then delete them again. Possibly it was some artifact from duplicating the other valve udt definition to create the one for the control valve 🤷‍♂️

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**Author:** ![andrew.budaiev](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/andrew.budaiev/32/72921_2.png) [@andrew.budaiev](https://forum.inductiveautomation.com/u/andrew.budaiev)\
**Post date:** [June 10, 2025, 12:18am UTC](https://forum.inductiveautomation.com/t/bug-udt-instance-non-existent-tag-reading-error-configuration-instead-of-bad-notfound/104623/2 "2025-06-10T00:18:37Z")

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Just had the same problem.

> [@nminchin](#):
>
> To fix it, I had to add the two non-existent tags to the definition and then delete them again

Thanks!