CD-RW disks are notoriously unreliable in my opinion. If you want to be persistent I`d reformat the disk and try again but reduce the write speed by half. I`ve also found that verification fails but the disc is useable anyway.
To be honest, ordinary CD disks cost about 12-16 pence these days and It`s hardly worth the effort to use rewritables, simply burn another disk.
It is also quite likely that your burner isn`t compatible with the media you`ve chosen. I`ve several CD-RW disks that won`t work in my laptop but are fine in my tower. Again it`s a little expensive buying different makes just to suit each burner.