Most viewed questions in Blockchain

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3 answers

Cannot find module 'fabric-network' - is my application installation done wrong?

First, install grpc and run it: $ npm ...READ MORE

May 20, 2019 in Blockchain by John
670 views
0 votes
1 answer

Unable to enroll user in new org

The thing is by default, fabric-ca only has ...READ MORE

Aug 24, 2018 in Blockchain by Christine
• 15,810 points
670 views
0 votes
1 answer

Getting Invalid number of parameters for “undefined” when deploying smart contract

Try something like this for contracts that ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 68,840 points
666 views
0 votes
1 answer

How to install truffle on Linux?

You can install Truffle using npm(node package manager). ...READ MORE

Feb 28, 2019 in Blockchain by Rishab
661 views
0 votes
1 answer

web3.eth.sendSignedTransaction() always return “Returned error: nonce too low”

This bit of code looks wrong: var rawTx ...READ MORE

Oct 1, 2018 in Blockchain by slayer
• 29,260 points
659 views
0 votes
1 answer

Php code to generate Ethereum wallets.

You can use web3.eth.accounts in web3js web3.eth.accounts.create(); With Php, ...READ MORE

Jul 27, 2018 in Blockchain by slayer
• 29,260 points
656 views
+1 vote
1 answer

What are the key functional differences between Hyperledger Composer and Fabric Javascript SDK?

Hyperledger Composer is an application development framework ...READ MORE

Apr 11, 2018 in Blockchain by Perry
• 17,090 points
656 views
0 votes
1 answer

How to efficiently hash (SHA 256) in golang data where only the last few bytes changes

You can try the following examples on ...READ MORE

Jun 27, 2018 in Blockchain by Aryya
• 7,340 points
655 views
0 votes
1 answer

Solidity error: SyntaxError: No visibility specified.

As mentioned in the error, you have ...READ MORE

Dec 12, 2018 in Blockchain by Omkar
• 68,840 points
648 views
0 votes
1 answer

How to retain the container state after shutdown/restart of Hyperledger Fabric network?

In a Dev environment, you can first ...READ MORE

Jul 17, 2018 in Blockchain by slayer
• 29,260 points
648 views
0 votes
1 answer

Hyperldger: Hyperledger Explorer not starting. Throws error

in "network-config" you should use lowercase 'org1' { ...READ MORE

Nov 8, 2018 in Blockchain by Omkar
• 68,840 points
645 views
0 votes
1 answer

Hyperledger Fabric:Error while creating channel unknown consortium

Firstly, replace DocChain with DocChainConsortium. Then run: docker-compose -f docker-compose-cli.yaml down --volumes ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 68,840 points
644 views
0 votes
1 answer

How to “unrecognized import path error” while using go for hyperledger fabric?

The solution to this problem is as ...READ MORE

Jul 27, 2018 in Blockchain by slayer
• 29,260 points
644 views
0 votes
1 answer

NodeJS POST Request Over JSON-RPC

You're missing the --header option: curl --request POST \ ...READ MORE

Sep 28, 2018 in Blockchain by digger
• 26,660 points
640 views
+1 vote
1 answer

Can't instantiate any chaincodes on peers of newly Added org

Seems like chaincode install may have been unsuccessful. Before ...READ MORE

Sep 20, 2018 in Blockchain by Perry
• 17,090 points
639 views
+1 vote
1 answer

what is use of msg.sender in solidity code?

msg.sender(address) function indicated the sender of the ...READ MORE

Apr 24, 2018 in Blockchain by Shashank
• 10,360 points
633 views
0 votes
1 answer

How to set chaincode path in Hyperledger Fabric?

For chaincode to properly run on your ...READ MORE

Jul 27, 2018 in Blockchain by digger
• 26,660 points
630 views
0 votes
1 answer

How can I get the same return value as solidity `abi.encodePacked` in Golang?

This is what I used:  package main import ( ...READ MORE

Sep 26, 2018 in Blockchain by slayer
• 29,260 points
622 views
0 votes
0 answers

Error: Unexpected token o in JSON at position 1

I have been working with Interacting a ...READ MORE

Mar 6, 2019 in Blockchain by saeedi
• 120 points

edited Mar 6, 2019 by Omkar 618 views
0 votes
1 answer

Hyperledger Fabric: How to create wallet using program?

You can do this by passing some ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 68,840 points
616 views
+4 votes
2 answers

How do I create a new block in Hyperledger Fabric?

This link might help you: https://github.com/hyperledger/fabric-sample ...READ MORE

Oct 11, 2018 in Blockchain by Sahu
606 views
0 votes
1 answer

Truffle compile compilation failed

This is a version compatibility problem. In ...READ MORE

Jan 17, 2019 in Blockchain by Omkar
• 68,840 points
601 views
0 votes
1 answer

How to solve “More than one instance of bitcore-lib found” error?

There is a temp solution here. ~/bitcore-explorers/node_modules/bitcore-lib/index.js line 7: bitcore.versionGuard ...READ MORE

Jul 25, 2018 in Blockchain by slayer
• 29,260 points
599 views
+1 vote
1 answer

How can I add image into my Hyperledger instance

In your registry, you can Base64-ify your ...READ MORE

Jun 8, 2018 in Blockchain by Aryya
• 7,340 points
599 views
0 votes
2 answers

Truffle compile/migrate not working

In my case, use sudo command. truffle compile ...READ MORE

Feb 20, 2019 in Blockchain by byoul
593 views
0 votes
1 answer

geth: Fatal: Error starting protocol stack: datadir already used by another process

It seems like geth is already running. ...READ MORE

Dec 5, 2018 in Blockchain by Omkar
• 68,840 points
584 views
0 votes
1 answer

eth.getBalance() always returns 0 in testnet

You are not connecting to the right ...READ MORE

Jul 24, 2018 in Blockchain by Christine
• 15,810 points
584 views
–1 vote
1 answer

Not able to install truffle

I know this is very frustrating, I ...READ MORE

Jan 17, 2019 in Blockchain by Omkar
• 68,840 points
583 views
0 votes
1 answer

How to solve “error: no objects passed to create” Error?

It seems like a problem with the ...READ MORE

Aug 1, 2018 in Blockchain by digger
• 26,660 points
581 views
0 votes
1 answer

Hyperledger Fabric peer command not found error.

This error occurs when the system can ...READ MORE

Jul 2, 2018 in Blockchain by Omkar
• 68,840 points
580 views
+1 vote
1 answer

Hyperledger Fabric: Got permission denied Docker daemon socket at unix:///var/run/docker.sock

You are getting this error probably because ...READ MORE

Nov 19, 2018 in Blockchain by Omkar
• 68,840 points
577 views
0 votes
1 answer

How to make POST request on C# to blockr.io

By default UploadValues doesn't format the data ...READ MORE

Aug 30, 2018 in Blockchain by digger
• 26,660 points
572 views
0 votes
1 answer

Cannot find package “google/protobuf”

Firstly, your import is wrong, you are ...READ MORE

Oct 1, 2018 in Blockchain by Perry
• 17,090 points
570 views
0 votes
1 answer

How can I deploy a HelloWorld contract on my testrpc network?

The problem lies in the command: truffle migrate Your truffle migrate command ...READ MORE

Apr 27, 2018 in Blockchain by Perry
• 17,090 points

edited Aug 10, 2018 by Omkar 570 views
0 votes
2 answers

How to check if bitcoin address is valid?

For Java, have a look at the ...READ MORE

Aug 20, 2018 in Blockchain by Omkar
• 68,840 points
567 views
0 votes
1 answer

Solidity invalid opcode error

In the for loop, your indexing going ...READ MORE

Aug 16, 2018 in Blockchain by slayer
• 29,260 points
567 views
0 votes
1 answer

REQUEST_TIMEOUT error in Hyperledger Fabric, Linux

My docker version was 1.7. And its ...READ MORE

Jul 6, 2018 in Blockchain by Christine
• 15,810 points
566 views
0 votes
1 answer

Hyperledger Fabric: How to access transaction ID in invoke function?

You can access transaction ID in Invoke ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 68,840 points
563 views
+1 vote
1 answer

How to write an ERC 721 contract?

You could go through the following links:  https://github. ...READ MORE

Jun 28, 2018 in Blockchain by Perry
• 17,090 points
562 views
0 votes
1 answer

How to solve “insufficient funds for gas * price + value” error?

Change the following line Credentials credentials = Credentials.create(firstAccount); To ...READ MORE

Aug 1, 2018 in Blockchain by slayer
• 29,260 points
560 views
0 votes
1 answer

Cant decode hex sting into decimal. Getting TypeError.

On the line where it shows error, ...READ MORE

Jul 6, 2018 in Blockchain by slayer
• 29,260 points
559 views
0 votes
1 answer

Getting Hash160 bitcoin address in python

There is a package to decode and ...READ MORE

Aug 24, 2018 in Blockchain by slayer
• 29,260 points
556 views
0 votes
1 answer

Hyperledger Fabric: Error endorsing chaincode: rpc error

Run the following commands and try again: docker ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 68,840 points
554 views
0 votes
1 answer

Not able to attach geth.ipc: Fatal: Unable to attach to remote geth: connect: connection refused

You should not mention double quotes for ...READ MORE

Dec 6, 2018 in Blockchain by Omkar
• 68,840 points
553 views
+1 vote
1 answer

Getting issues while Sending signTransaction with web3.js

The chain ID for ropsten is 3. ...READ MORE

Mar 28, 2018 in Blockchain by Johnathon
• 9,090 points
550 views
0 votes
1 answer

How do I send back ethers to the sender of the tokens in a smart contract?

Whenever a smart contract receives ether via ...READ MORE

May 30, 2018 in Blockchain by Perry
• 17,090 points
546 views
+1 vote
1 answer

What is the difference between if() and require() statement in solidity??

If() and require() have separate functions and ...READ MORE

Apr 18, 2018 in Blockchain by Shashank
• 10,360 points
546 views
0 votes
1 answer

How to Query hdfs with Spark Sql

Yyou can achieve this by creating Dataframe. val ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,260 points
545 views
0 votes
1 answer

Calling function in truffle console error

Inside Truffle console ContractName.deployed().then(function(instance){app = instance}) app.adopt(23)//call method on ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 68,840 points
543 views
0 votes
1 answer

Solidity ParserError: Expected identifier but got '='

Hey, the solidity grammar doesn't allow assignments ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 68,840 points
541 views