0

I'm trying to mint an NFT using Candy Machine UI v3 on the Solana network, but I'm encountering errors when attempting to confirm the transaction in Phantom Wallet. Here are the details:

Environment:

  • Network: Solana devnet
  • Wallet: Phantom
  • UI: Candy Machine UI v3
  • RPC: Helius Devnet RPC

Error messages:

  1. "Failed to simulate the results of this request. Confirming is unsafe and may lead to losses."
  2. "There was a problem estimating the fee for this transaction. It may fail."
  3. "Couldn't fetch network fee"

My .env configuration:

REACT_APP_CANDY_MACHINE_ID=<my id>
REACT_APP_SOLANA_NETWORK=devnet
REACT_APP_SOLANA_RPC_HOST=https://devnet.helius-rpc.com/?api-key=<my key>
SKIP_PREFLIGHT_CHECK=true

I've tried the following:

  • Ensuring I have sufficient SOL in my wallet (devnet mode)
  • Checking the Candy Machine configuration
  • Verifying the RPC endpoint is working

What could be causing these errors, and how can I resolve them to successfully mint my NFT?

Any insights or troubleshooting steps would be greatly appreciated.

Here is the picture of my Wallet when i click Mint button:

Phantom Wallet

Improve this question

1 Answer 1

Reset to default
1

„Couldn't fetch network fee“ and “There was a problem estimating the fee for this transaction. It may fail“ unfortunately right now is normal with phantom on devnet. It would still go through though and work on mainnet.

The first message is more interesting. The transaction is built incorrectly. This can have a ton of reasons like not all requiredaccounts being passed into the tx. Maybe you are using a guard that the UI does not support?

What I see as most likely though is that the ui is not compatible to your Candy machine. V3 has to different internal versions. Account Version 1 and 2. latest sugar CLI and JS SDK creates account version 2. You can find your Account version e.g. when viewing your candy machine on explorer.solana.com. Make sure that they are compatible. This ui here for example would be compatible to account version 2: https://github.com/MarkSackerberg/umi-cmv3-ui-inofficial/

Improve this answer
2
  • This is my guard config, does it compatible? Thanks you very much for your enthusiastic answer ``` "guards": { "default": { "solPayment": { "value": 0.01, "destination": "2ZeySJZ8b3qKMpwwnqWdsQQSTvr4YTNx6Ewjhzy56ts1" }, "botTax": { "value": 0.001, "lastInstruction": true } } }, ```
    – Tuan Thanh Vo
    Commented Aug 14 at 16:32
  • Depends on the ui and account version you are using
    – Mark Sackerberg
    Commented Aug 24 at 15:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.