The given value for a taxonomy field was not formatted in the required <int>;#<label>|<guid> format

Question

I have the following code to set the column default values for a library:-

var corpTypetaxValue = listItem["CorpType"] as TaxonomyFieldValueCollection;
var corpTypeFieldValueArray = corpTypetaxValue.Select(taxonomyFieldValue => $"1033;#{taxonomyFieldValue.Label}|{taxonomyFieldValue.TermGuid}");
context.ExecuteQuery();
var ttt = String.Join(";", corpTypeFieldValueArray);  
bb.SetFieldDefault(context.Web.GetFolderByServerRelativeUrl(webrelativeurl + "/" + i2["TemplateListUrl"].ToString()+ "/"+mainfoldername.ToString()), "CorpType", String.Join(";", corpTypeFieldValueArray)); 

the above code will work well if the CorpType contain single term, but if it contain multiple terms I will get this error when I try to modify the column defaults from the UI:

The given value for a taxonomy field was not formatted in the required ;#| format.

Answer 1

To include multiple taxonomy values, the values should be separated by ;#.

Example:

44;#USA|c1815b1d-346f-4ce1-b2cb-15df5e12b0b3;#45;#INDIA|e141d775-7a3b-40aa-a680-98039b375828

Source:

Update Managed Metadata column Default Value(s) using CSOM - C#