X_E2E_APP_FAILED
Means
the app an e2e run spawned did not come up
Typical cause
the reset, the seed or the boot of the app the e2e step spawned failed. The cause names the step and carries its output. The app runs on a throwaway ULTIMATE_STATE_DIR (its own embedded database, disk and dev lock), so your own .x/ is untouched
Fix
x dev --json: boot the same app by hand and read why it would not start