Import message base entry - error "Updates are not allowed"
We have some custom message base entries for our AAQ page that will direct the customer to a company website. When we clone from prod to a test site, we want these message base entries updated so that the links point to a development website instead. I created a csv file for each of the message base entries involved, updating the links and attempted to import the file. I'm getting "updates not allowed" for each row. I have included all of the mandatory columns: key, type, length and text. Any advice on what could be wrong?
Version (include the version you are using, if applicable):