When you run system.tag.getConfiguration, it returns a list of tag dictionaries related to your tag. You can’t just write back to that list. You can take that list and modify it then use system.tag.configure() to write back to your tag. The last example in system.tag.configure looks close to what you were trying to do there except you added [‘value’] to it so I’m assuming you have more to your script your not sharing?
I had the same issue in a script I wrote before Inductive added datatypes to UDT parameters. You can no longer just assign a value directly to a parameter. You’ll need to use the “setValue” method.
The other thing is that you can simply write to the UDT instances’ parameters directly using system.tag.writeBlocking(['path/UDTInstance/Parameters.Param1'], [10])