Unwanted Read Only column in SharePoint - how do I get rid of it?

[faxmaskin]

Hi!

Usually just searching this awesome forum saves my day and solves all my problems, but this time I'm close to a deadline and I can't tell if it's my patience or my searching that is lacking. Anyhow, I building a flow that's copies, creates and converts files around different SharePoint lists and libraries (without any trouble). The problem arises in an otherwise unproblematic action, namely the "Update file properties" action for a multi-select column in SharePoint Document Library (which never troubled me before).

The error message reads as follows: 

"The 'inputs.parameters' of workflow operation 'Uppdatera_metadata_för_originalfil' of type 'OpenApiConnection' is not valid. Error details: The API operation does not allow writing a value for parameter 'item/M_x00e5_lgrupp[0]/Id'. This parameter is read only."

I hope someone quickly can spot what I can't see and that the Swedish in the picture doesn't confuse all to much. 😊

Thanks a million! 

/Joakim

[ChristianAbata]

hi @faxmaskin  It looks like a limitation This parameter is read only so you can't change the parameter my friend.

[faxmaskin]

@ChristianAbata, Any insight to why that is? Hasn't encountered it before with similar flows. I tested to recreate a column with multi-select but the problem was the same. 

When I rearrange my flow so that the "Update file properties" action is inside a "For Each" loop the flow is successful, but only the last value from my multi-select column is transferred to the other library/list. 

[faxmaskin]

I found proof of that this used to work fine in this post: 
https://powerusers.microsoft.com/t5/Building-Flows/Update-a-List-Item-Multiple-Select-Choice-Field/t...

@v-yuazh-msft showed the solution that I've been using, with using the entire array. But for some unknown reason it now states that my SharePoint column is ReadOnly, which (again) isn't something I've set up or want. 

[faxmaskin · Accepted solution]

Turns out I was to blame, the Read Only was caused by a parallel process that was trying to write to the same field... When I rearranged the flow to run sequentially it worked like a charm. 😎