Fixer, a droid of the MSE-6 series repair droid type, resided on Zoh, a planet comprised of scrap. On this world, Fixer and other droids followed the leadership of Jek-14. Soon after the Freemakers' arrival on Zoh, where they sought Jek-14's assistance, N-3RO, a thankless droid, instigated a rebellion of droids against Jek-14 and the Freemakers. N-3RO was successful in persuading the other droids, Fixer included, that humans are untrustworthy. Their attempt failed, leaving N-3RO stuck on Zoh, now equipped with a restraining bolt.
The initial appearance of Fixer was in LEGO Star Wars: The Freemaker Adventures, and he was later integrated into canon through Star Wars: Droidography.