Welcome to the forum 
From your error info, the drive is having a problem reading the disc back/veryifying. I would suspect the discs. You might like to follow the advice of Homeless above.
Most of the time, the only safe bet for DL media is Verbatim. Any thing else can either fail to burn (as in your case), or playback maybe a problem if the burn completes.
Occasionally, non-Verbatim DL discs can work well, but from what I’ve read around the forum, these cases are few and far between. 
Edit: Very unusual, and those discs must be particularly bad if the Pioneer can’t do anything with a lot of them - Pioneers usually do well with sub-par media.