Needlework is the other folder I already have on the disc.
Did you give the disc itself a name? It sounds to me as if the alert you quoted was referring to the disc, not the folder.
In any case, if I'm interpreting your earlier thread correctly, the disc you purchased on eBay was a DVD-R. If so, it's not re-writable; you can write to a DVD-R or a DVD+R once, and thereafter it's read-only. To continue to be able to write to a disc, it needs to be a DVD-RW or a DVD+RW.
