It was announced several weeks in advance that part of episode 25 wouldn't be finished in time for the theatrical release due to quality issues. They apologied for that. I thin kthey gave an extra item at the theaters to compensate, but it was like a poster or something. The BD was also delayed a month for the same reasons.
It is guessed what is missing isn't plot critical, while episode 26 was plot critical, so they spent their time on that and left 25 until later. What is missing is about 8 minutes of material.
The episode will be on TV in two weeks. Complete for the first time.