Base switches to 200-millisecond blocks tomorrow. One of the chains built on top of it can't keep up, so it's shutting down.
Horizen's L3 closed its bridge to Base at 8 AM ET today and snapshotted every balance. Base's Denim upgrade activates Nov. 5 at 18:00 UTC (1 PM ET). About 40 minutes later, Horizen says, the L3 "can no longer include user transactions, permanently." Its infrastructure provider confirmed there's no fix.
Leftover ZEN, staking positions and ETH above 0.001 will be returned on Base by the DAO, expected in the second half of November. USDC.e won't: it's Stargate's token and "not covered by the DAO return."
Horizen says it was already planning to move out. Base just picked the moving date.