Cannot copy DVD+r disc

Using Phillips Magnavox Vcr DVD combo manufactured by Funai.
Copied vcr to disc using DVD+r and finalized
DVD plays on my TV and on computer but if I try to do a copy using Sonic the data gets read in but the read does not complete to ask for a writeable disc to be inserted. After the incomplete read there is a yellow symbol with an exclamation point in the middle. Could not decipher the meaning of the error symbol
Anybody have any suggestions.
Thanks