I recently deployed my NFT project on the Polygon mainnet after successfully testing it on local, testnet, and Mumbai testnet environments. Everything was functioning well during the preliminary tests—buying, selling, and creating NFTs posed no issues.
However, after moving to the mainnet, I encountered a significant problem: I can’t sell any of the NFTs I created. While I can still buy and mint NFTs without trouble, trying to sell them results in failure each time.
I’m utilizing technologies like JavaScript, React with Next.js, Solidity for creating the smart contracts, and connecting via MetaMask. The error message I receive is “MetaMask - RPC Error: Internal JSON-RPC error” whenever I attempt a sell operation.
Has anyone else faced similar obstacles transitioning from test networks to the Polygon mainnet? What might be causing this discrepancy between my testing and the actual deployment?
The JSON-RPC error you’re encountering is likely due to insufficient gas estimation when transitioning to the Polygon mainnet. I experienced a similar issue; while my gas limits were adequate on the test network, they were too low for mainnet transactions due to higher congestion and different pricing.
It’s crucial to examine your contract’s sell function, particularly any external calls or complex calculations that may fail under mainnet conditions. I found that my marketplace fee computations didn’t hold up when I deployed.
I recommend manually setting your gas limits higher, instead of relying on automatic estimations. Additionally, verify that all contract addresses and dependencies are designated for the Polygon mainnet and not remnants of the test networks, as hardcoded values can lead to issues.
Oh wow, that’s frustrating! I’m curious though - when you buy and mint NFTs without issues, are you buying from other users or just minting new ones from your contract?
I’ve seen the approve function act weird on mainnet vs testnets. When selling an NFT, your contract needs approval to transfer it from your wallet to the buyer. Sometimes that approval process works differently on mainnet.
Have you checked the transaction logs or polygonscan to see exactly where it’s failing? “Internal json-rpc error” is pretty vague but there’s usually more detail if you dig into the actual transaction attempt.
Are you using the same wallet address you used for testing? People sometimes switch wallets and forget about approval states. Double-checked that your marketplace contract has the right permissions?
What does your sell function look like? Is it doing calculations or external calls that might timeout on mainnet due to network congestion?
sounds like a mainnet issue. same thing happened to me - my contract was still using mumbai addresses for dependencies even tho i switched everything else. check your polygon rpc endpoint too. metamask sometimes defaults to unreliable ones that randomly fail. switch to the official polygon rpc or use alchemy/infura instead.