I am following this tutorial on how to reserve a paraID https://docs.substrate.io/tutorials/connect-other-chains/local-parachain/

I have the two Polkadot v0.9.24 validators running and I can see "peer(1)" in their logs so those two validators can see each other.

Then I go to open PolkadotJS https://polkadot.js.org/apps/?rpc=ws%3A%2F%2F127.0.0.1%3A9944#/parachains/parathreads

in Accounts > My accounts tab > I see Alice has only 1 MUnit

ALICE 5Grwva…GKutQY sr25519 1.0000 MUnit

Is that enough ? How can I get some more?

The tutorial says You must have a sufficient funds to reserve a ParaID. Refer to your target relay chain to determine the number of tokens required.

what does this mean?

Then when I click on Network > Parachains > Parathreads tab > use the + ParaId button >

It says Reserve from Alice. ParachainID 2000. Reserved Deposit 5.000 Units

Then I click on submit, and get this error message:

1002: Verification Error: Runtime error: Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed WASM backtrace: 0: 0x354ef6 - <unknown>!rust_begin_unwind 1: 0x872e - <unknown>!core::panicking::panic_fmt::hc6c29bb1e9ac0604 2: 0x145d3a - <unknown>!TaggedTransactionQueue_validate_transaction : RuntimeApi, Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed\nWASM backtrace:\n\n 0: 0x354ef6 - <unknown>!rust_begin_unwind\n 1: 0x872e - <unknown>!core::panicking::panic_fmt::hc6c29bb1e9ac0604\n …

Why is this not working? I am using the latest Polkadot v0.9.24.

1 Answer 1



In PolkadotJS > Settings > Developer > Reset to restore it to the original empty JSON format

Stop the 2 Polkadot validators

Purge those 2 validator's DB locally

cd $POLKADOT_BUILD_DIRECTORY && rm -rf /tmp/relay/alice/chains/rococo_local_testnet/db/full

cd $POLKADOT_BUILD_DIRECTORY && rm -rf /tmp/relay-bob/chains/rococo_local_testnet/db/full

Restart the 2 validators then follow the tutorial

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