Sprite slicing problem

I have a problem.

I imported a sprite sheet into Unity with the following dimensions:

1024 tall

17664 wide

individual sprites are as follows:

1024 tall

768 wide

when I click the splice button, the menu pops out as it should with the correct options, but when I click splice (when I click splice if I have selected automatic, by cell, or by count) nothing happens.

The only notable things are a few errors in the console that are as follows:

requested size is too large

requested size is too large (not a typo, there are two of this error)

texture has out-of-range width/height

failed to create textures because of invalid parameters

help?

(upon further inspection, it appears something is too large, what can I do? Can i do something without creating a new spritesheet?)

Any luck finding answer ?