I have been trying to mint an NFT using the native TokenMintTransaction() function, but it keeps returning the MAX_NFTS_IN_PRICE_REGIME_HAVE_BEEN_MINTED error. Since the documentation is terrible I have a hard time finding out what the error actually means.

I used the exact same code as explained in their docs:(https://docs.hedera.com/guides/getting-started/try-examples/create-and-transfer-your-first-nft)

let nftCreate = await new TokenCreateTransaction()
  .setTokenName("diploma")
  .setTokenSymbol("GRAD")
  .setTokenType(TokenType.NonFungibleUnique)
  .setDecimals(0)
  .setInitialSupply(0)
  .setTreasuryAccountId(treasuryId)
  .setSupplyType(TokenSupplyType.Finite)
  .setMaxSupply(250)
  .setSupplyKey(supplyKey)
  .freezeWith(client);

let nftCreateTxSign = await nftCreate.sign(treasuryKey);
let nftCreateSubmit = await nftCreateTxSign.execute(client);
let nftCreateRx = await nftCreateSubmit.getReceipt(client);
let tokenId = nftCreateRx.tokenId;

CID = ["**********************************************"];

let mintTx = await new TokenMintTransaction()
  .setTokenId(tokenId)
  .setMetadata([Buffer.from(CID)])
  .freezeWith(client);

let mintTxSign = await mintTx.sign(supplyKey);
let mintTxSubmit = await mintTxSign.execute(client);
let mintRx = await mintTxSubmit.getReceipt(client);

So what am I doing wrong here?