Because there is not enough storage space on your ipad for it -_- , a whole tv series is actually huge (about 20 to 30 GB for just 1 season) so either delete some stuff or only download a couple episodes on it, watch them, delete them and download some more.
never enough!
For download space
file server
If you have an apple computer then you can't download it. If it's not that then your computer is to old.
Yes !
yes
Not enough storage space?
put it in storage
Some devices do not contain storage devices, or do not have enough storage space needed by a particular user. Extra storage devices such as an external hard drive can be utilized.
If your phone is displaying that message, it means that your phone is running out of space in its memory. You should delete unnecessary pictures, videos, texts, and saved voice messages so you can have more storage space.
That means you've run out of storage space. Either get a bigger storage drive or delete unwanted programs.
You migh not have enough space in hardrive to download try buying another hardrive or deleting some stuff on hardrive until u have enough space for DLC