The reworked long-term memory system breaks backwards compatibility with NPC memory files from versions before 1.0.0. Load the old save in the new version, then export the memories again, then you can import them wherever you need.
They didn't have much long-term memory before 1.0.0 in the first place. Versions before 1.0.0 kept track of a small blob of general relationship info. Versions after 1.0.0 compress information from the short-term memory into highly concise chunks that are then committed to long-term memory.