Warning:Element.SetParameterByName operation failed. The parameter is read-only

Hi Guys,

I am new user for Dynamo.

I have created Dynamo scripts to add Suffix ‘_SD’ in sheet number.

But if I run my dynamo script, suffix ‘_SD’ is getting added in most of sheet number but suffix for few sheet numbers is not getting added.

Also warning ‘Element.SetParameterByName operation failed. The parameter is read-only’ is appearing at node ‘Element.SetParameterByName’.

Kindly advise.

Thank you in advance for your co-operation.

Can you preview the output of the node which has the warning? Also confirm your coworkers don’t own any of the sheets by having them and you sync.

Hello Jacob,

Thank you for your reply.
I am using this Revit script in model which is created on my local drive.
Please refer below image with output preview.

This might be caused by the resequencing order of your sheet numbers, whereby a sheet which is yet to be renumbered owns a number which you are attempting to use to renumber another sheet, hence its read-only as you haven’t ‘freed’ it up yet.

If that is the case use BimorphNodes Sheet.RenumberRename as it’s built to circumvent this issue.

There’s some more info about this phenomenon here:

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Hello Thomas,
Thank you for you reply.
Please let me know that i have to use BimorphNodes ‘Sheet.RenumberRename’ node instead of ‘Element.SetParameterByName’ node?
Because i am beginner in dynamo.

I wouldn’t think it is a sequencing issue since he is merely appending things to the end of the sheet numbers. Therefore I don’t think he would have any duplicates. The “null” in the middle of the output is interesting, but appears to align with this issue.


Still seems like using a different parameter route or the node you have created would be a good way to go.

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Hello Thomas,

I used BimorphNodes ‘Sheet.RenumberRename’ & finally got expected result.
See below image.

Once again thank you all of you for your supports & advice.

This is good platform for me to learn new thing in Dynamo & revit.