{"record":{"id":"d3c440a7da3a0fbc","repo":"hyperledger/fabric","slug":"cannot-decode-the-block-d","errorCode":null,"errorMessage":"Cannot decode the block %d","messagePattern":"Cannot decode the block (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"internal/ledgerutil/verify/verify.go","lineNumber":112,"sourceCode":"\n\t\terr = blockResult.writer.OpenList()\n\t\tif err != nil {\n\t\t\treturn false, err\n\t\t}\n\n\t\tvar previousHash []byte\n\t\tfor i := firstBlockNumber; i < info.GetHeight(); i++ {\n\t\t\t// Retrieve the next block\n\t\t\tresult, err := iterator.Next()\n\t\t\tif err != nil {\n\t\t\t\treturn false, err\n\t\t\t}\n\t\t\tif result == nil {\n\t\t\t\tbreak\n\t\t\t}\n\t\t\tblock, ok := result.(*common.Block)\n\t\t\tif !ok {\n\t\t\t\treturn false, errors.Errorf(\"Cannot decode the block %d\", i)\n\t\t\t}\n\n\t\t\tif block.Header.Number != i {\n\t\t\t\treturn false, errors.Errorf(\"The next block is expected to be %d but got %d\", i, block.Header.Number)\n\t\t\t}\n\n\t\t\t// Perform checks for this block\n\t\t\tcheckResult, err := checkBlock(block, previousHash)\n\t\t\tif err != nil {\n\t\t\t\treturn false, err\n\t\t\t}\n\n\t\t\t// If any error is found, flag as so, and vice versa\n\t\t\tif !checkResult.Valid {\n\t\t\t\tledgerErrorFound = true\n\t\t\t\tblockResult.erroneousBlocks += 1\n\n\t\t\t\t// Record the error details in the JSON","sourceCodeStart":94,"sourceCodeEnd":130,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/internal/ledgerutil/verify/verify.go#L94-L130","documentation":"VerifyLedger iterates blocks from the block store via an iterator that returns generic proto messages. Each result must be decodable to *common.Block; if the type assertion fails, the ledger cannot be verified because the object at position i is not a valid block.","triggerScenarios":"The block store iterator (blkstorage) returns a non-block proto message at iteration position i, e.g. a corrupted block store index or a malformed block file on disk inside ledgersData.","commonSituations":"Running 'peer node verify-ledger' against a ledger directory that has been manually edited, copied partially, or corrupted by an abrupt kill during block flush; disk corruption or wrong file placed in the blockstore directory.","solutions":["Re-run verification on a backup or a freshly re-fetched ledger to confirm which block position is corrupted","Inspect the block files under ledgersData/blockAndTransaction for corruption and restore from a peer snapshot/backup","If the ledger is irrecoverable, reset the peer (peer node reset) and re-sync blocks from orderers/peers","Check disk health and filesystem errors; replace failing storage"],"exampleFix":null,"handlingStrategy":"validation","validationCode":"// Before verify-ledger, sanity-check the block store directory has block files\nimport os\nfunc blockStoreLooksPopulated(fsPath string) error {\n  entries, err := os.ReadDir(filepath.Join(fsPath, \"ledgersData\", \"blockAndTransaction\"))\n  if err != nil { return err }\n  if len(entries) == 0 { return fmt.Errorf(\"block store empty at %s\", fsPath) }\n  return nil\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Never manually edit or partially copy ledgersData directories","Take consistent snapshots of peer data only while the peer is stopped","Monitor disk health on nodes hosting peer data","Keep a verified backup before running ledger maintenance"],"tags":["ledger","corruption","fabric"],"backgroundTag":"ledger-data-corruption","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}