# Mutating a QualifiedValue object causes weird bugs

**URL:** <https://forum.inductiveautomation.com/t/mutating-a-qualifiedvalue-object-causes-weird-bugs/41696>\
**Category:** Ignition\
**Created:** [December 21, 2020, 6:18pm UTC](https://forum.inductiveautomation.com/t/mutating-a-qualifiedvalue-object-causes-weird-bugs/41696 "2020-12-21T18:18:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![AlThePal](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/althepal/32/3603_2.png) [@AlThePal](https://forum.inductiveautomation.com/u/AlThePal)\
**Post date:** [December 21, 2020, 6:18pm UTC](https://forum.inductiveautomation.com/t/mutating-a-qualifiedvalue-object-causes-weird-bugs/41696/1 "2020-12-21T18:18:00Z")

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We’ve found that in Ignition 8.1.1 when you read a tag using _system.tag.readBlocking_ it is possible to write to the QualifiedObject and update the value of the tag. While the value is updated, anything showing the value doesn’t get updated until you refresh it e.g. the Tag Browser and View nodes.

When you then right-click on a tag in the Tag Browser and select _Restart Tag_ the original value is shown.

This seems like a serious bug. Even though the API shows that QualifiedValue objects have setQuality and setValue functions I can’t think when they should be used. I would have thought they should be immutable.

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [December 22, 2020, 3:40am UTC](https://forum.inductiveautomation.com/t/mutating-a-qualifiedvalue-object-causes-weird-bugs/41696/2 "2020-12-22T03:40:35Z")

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Interesting. That the mutations don’t generate events in the tag system is not unusual. Same behavior if you setDataAt() on a dataset retrieved from a tag. Probably happens with document tags, too, even without this qualified value behavior.

Is this behavior new to 8.1.1?