I am unsure if I submitted this correctly, but the Arcane Trickster Archetype of the Rogue Class should have four usable spells at level five, excluding cantrips. I am only able to add one before receiving the "You cannot select any more abilities." error.
Roguish Archetype in SRD5 is limited to "Thief", we do not have Arcane Trickster. I cannot fix what doesn't exist.