"You are about to create a multisession write once DVD disc Session no.2 and above will not be readable with some DVD - ROM drives and operating systems prior Windows XP"
Then You have two options:
- Burn Multisession Anyway
- Burn without Multisession
what exactly is burning multisession
Let me explian what is multisession burning before we go any deeper on this issue,for data or video, select a multisession burn, or finalize your disc. With write-once DVD-R and +R, and CD-R, you can choose to add data to the disc in separate burning sessions over time (called a multisession write), or lock a disc so you can't add more content (called disc finalization). In short multisession means that after you burn some stuff onto the dvd, you can come back and burn some more if there is space left.
Technically,i really have no idea why we can't 100% continue the multisession session,from my own experience and after wasted fews DVD, I will avoid using Multisession..You can burn but If you have to change your DVD player/rewriter,or bring it to another player, you may not be able to access any files on that DVD..sometimes,with the same writer ,you just can't found the files you have burned ,it appear on Nero but you just can't access it..
How to fix the problem
My solution is to create a folder on my HDD, throw in files that i am going to burn ,and when it's got about 4.7GB in it, burn to DVD in a single session. No risks that way.And DVD-RW, DVD+RW seem to act more "stable"compare to DVD-ROM, DVD-R, DVD+R, DVD+R DL, DVD-R DL, DVD-RAM.