After you have published the current version of your island, if you make updates to the persistable data, any stored data from a previous version of the island must be supported in later versions of the island.
To ensure this, a backwards compatibility check is run in UEFN and a compilation failure occurs if the Verse code is no longer compatible with the currently published version.
You will have to just add your verse script back, if you don’t remember how your verse persistence was structured you could try to find a copy of it by following the steps from this post to recover verse files from previous launched sessions/publishes
