# "no viable alternative at input'\*tag\*'" error

**URL:** <https://forum.inductiveautomation.com/t/no-viable-alternative-at-input-tag-error/55257>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [January 21, 2022, 4:58pm UTC](https://forum.inductiveautomation.com/t/no-viable-alternative-at-input-tag-error/55257 "2022-01-21T16:58:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Micah\_Carr](https://avatars.discourse-cdn.com/v4/letter/m/bbe5ce/32.png) [@Micah\_Carr](https://forum.inductiveautomation.com/u/Micah_Carr)\
**Post date:** [January 21, 2022, 4:58pm UTC](https://forum.inductiveautomation.com/t/no-viable-alternative-at-input-tag-error/55257/1 "2022-01-21T16:58:03Z")

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I am trying to change the position and size of an object from a tag. The code works with a hardcoded value, or if I link it to a parameter, but when I try to link it to a tag I get a “no viable alternative at input” error. I don’t understand why this error is occurring. I have also tried to use the script in a main window instead of the template incase it was a scope issue, but the same error occurs.

What am I doing wrong?

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/1/01a2fc8a990d671d60e2aeda0ba402f17e793f6e.png)

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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:** [January 21, 2022, 5:07pm UTC](https://forum.inductiveautomation.com/t/no-viable-alternative-at-input-tag-error/55257/2 "2022-01-21T17:07:27Z")

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You are trying to use a bare tagpath in a jython script. You must use a `system.tag.read*()` function to go get the tag value, where the tagpath is supplied as a string.