"Store as recurring transaction" for General Journal entry is greyed out, why?

I'm taking over from a predecessor and there is an old recurring general journal transaction saved. I want to overwrite it, but in the "Create General Journal" dialogue box the button to "store as recurring transaction" is greyed out. Is there a setting somewhere for this, or an alternative way to create recurring transactions? I'm able to store recurring transactions in both the sales and purchasing journal dialogue boxes, just not in the general journal box.