Thanks for the report. We've seen bad discs from Ritek and Philips in the past. I had some Ritek discs fail after about three years. I would suggest recovering your data now if at all possible, and burning to more reliable media if you have to have it on discs.
Verbatim mid code BD-R media has worked well for me so far, as have the FTI made discs using TDK mid codes. Many around here also recommend Panasonic discs.