Hey everyone,
I’m having some trouble with HardHat when I try to switch between Polygon testnet and mainnet. It’s really weird.
Here’s what’s happening:
- Everything works fine on testnet (Mumbai).
- I switch to mainnet and try to deploy or mint - boom, error city!
- The error I keep getting is ‘ProviderError: invalid sender’.
I tried changing the RPC endpoint in my config file. When I use matic-mumbai.chainstacklabs.com, things seem to work again. But I’m not sure why this is happening or if it’s a common issue.
Has anyone else run into this? Is it a HardHat thing or a Polygon thing? Any ideas on how to fix it for good?
Thanks in advance for any help!
hey there! i’ve been messing around with hardhat and polygon too, and man, that error sounds familiar. have you checked if your account has enough MATIC for gas on mainnet? that’s caught me off guard before 
also, i’m curious - what version of hardhat are you using? sometimes updating to the latest can fix weird issues like this. oh, and have you tried using a different wallet? maybe there’s something funky going on with the one you’re using now.
btw, have you noticed any other differences between how things work on mumbai vs mainnet? i’ve been thinking about moving some of my projects to mainnet soon, so i’d love to hear about your experience!
I’ve encountered a similar issue when working with HardHat and Polygon. The ‘invalid sender’ error often stems from a mismatch between the network configuration and the account you’re using. Double-check that your private key or mnemonic in the HardHat config matches the account you intend to use on mainnet. Also, ensure you have sufficient MATIC in your account for gas fees on mainnet.
Another potential cause could be outdated RPC endpoints. Polygon occasionally updates their RPC URLs, so it’s worth verifying you’re using the most current ones. For a more stable solution, consider using a dedicated node service like Infura or Alchemy for both testnet and mainnet connections.
If the issue persists, try clearing your HardHat cache (npx hardhat clean) and updating your dependencies. Sometimes, older versions of HardHat or its plugins can cause unexpected behavior when switching networks.
yo, i had this prob too. it’s annoying af. try clearing ur cache (npx hardhat clean) and update ur stuff. sometimes the old versions mess things up. also, check ur account has enough MATIC for gas on mainnet. if that don’t work, maybe try a different RPC. good luck bro