In the project I'm working on, about 18 copies of this error appears. I currently suspect it's related to the number of mutations I've registered. I will investigate soon. As the title says, minimal case to follow.
[fulcro.client.impl.application] Mutation fulcro.inspect.ui.transactions/add-tx failed with exception Error: Assert failed: Path [:fulcro.inspect.ui.transactions/tx-list-id [:fulcro.inspect.core/app-id some-app.ui.root/Root] :fulcro.inspect.ui.transactions/tx-list] for append must target an app-state vector.
(vector? (get-in state data-path))