This is a big "what if" let's say some time in 1103 the Jump Drive suddenly stopped working, the reason is unknown. Nobody knows why, and it's not really important either, but what happens to the Third Imperium and all the other Interstellar nations of Charted Space? Everything else continues to work but the Jump Drive, when the Jump Drive is activated, nothing happens. Ships that were in Jump Space at the time of this happening continue on their journeys until they exit jump space and then those jump drives never work again.
Maneuver drives work as before. Gravity vehicles work as usual, the only thing that doesn't work is the Jump Drive. How would society adapt in the various inhabited systems? There would still be starships, except they go slower than light, but most can achieve rather high percentages of light speed. Low berths would become popular because trips would now take years to decades. Some low population worlds would have serious problems and might have to be abandoned. Anything else you can think of?
Maneuver drives work as before. Gravity vehicles work as usual, the only thing that doesn't work is the Jump Drive. How would society adapt in the various inhabited systems? There would still be starships, except they go slower than light, but most can achieve rather high percentages of light speed. Low berths would become popular because trips would now take years to decades. Some low population worlds would have serious problems and might have to be abandoned. Anything else you can think of?