SP List - update existing choice column to allow for multiple selectioins?

[Bryan123]

I have a SP list with existing columns created as Choice.  I would like to update those columns to allow for multiple selections.

SP appears to want to let me but I get an error when trying to save.  Am I doing something wrong or are you only able to do this with new columns and you are not able to update an existing column?

[#2]

@Bryan123 

I've not done this for a while but in earlier versions of SharePoint, moving from a single choice to a multiple choice column would work quite easily.  How many options have you used in the column?

If it doesn't work, than create as new the multiple choice field and use quick edit to copy paste the options over.

[#3]

@Steven Andrews  the issue is not going from a single choice to a multiple choice column. The issue is going from a multiple choice (single selection) to a multiple choice (multiple selection) column.

I have 30+ columns so rebuilding all the columns to allow for multiple selections is not feasible

[#4]

I am having the same issue. Did you ever find a fix to the issue?