Question for data write of derived tag


I have a UDT derived tag as shown in below snapshot. I use the OPC content as DataSource and use jsonGet/jsonSet to read/write its member.
The jsonGet function works fine and can reflect the values from OPC source as shown in snapshot 1, but it seems that jsonSet function doesn’t work when I update its value.
For the writing expression: I use “jsonSet({source}, ‘X’, {value})”
When I udpate the value of X in the tag direcotry or using the system.tag.write(’[VisionProvider]VectorTag/X’, value)
, it pops below error info in the log and the writing of value wil fail.

On: [client]Window Titles
20:23:03.149 [AWT-EventQueue-0] ERROR com.inductiveautomation.ignition.designer.tags.util.TagUtilities - Error writing to X.value: Error_ExpressionEval

So could anyone give some suggestions?
Thanks in advance.

What version of Ignition is this? I set up something similar and don’t have any problems with the writes.

@Kevin.Herron my version is 8.0.4nightly

It works on my Ignition now.
The error was caused by the update of UDT type is not synchronized with the instanced tag.

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