Good day all,

Trying to create a document set to store some documents related to a list item and I can create the docset just fine, but if I try to assign values to the user and date properties of the document set I get the following errors:

When attempting to set user field: Failed to create item. Invalid data has been used to update the list item. The field you are trying to update may be read only.

When attempting to set DateTime field: Failed to create item. The file or folder name contains characters that are not permitted. Please use a different name.

I found some advice on this blog, but his resolution didn't work for me either. I keep getting the same error whether I pass i:0#.w|domainusername, -1;#domainusername or domainusername

So the solution I found was to create the document set and then use the Update Item action to update the fields after the docset was created. This worked splendidly! Hope this helps you!