Script execution failed on commit at Main:25:20: Attempt to fetch or exercise a contract not visible to the reading parties. Contract: #0:0 (UserAdmin:Issuer) actAs: 'Alice' readAs: Disclosed to: 'UserAdmin' Ledger time: 1970-01-01T00:00:00Z

Questions
1

I got this error in main.daml file on setup script

module Main where


import Token
import UserAdmin

import Daml.Script



setup : Script ()
setup = script do
-- user_setup_begin
  alice <- allocatePartyWithHint "Alice" (PartyIdHint "Alice")
  bob <- allocatePartyWithHint "Bob" (PartyIdHint "Bob")
  charlie <- allocatePartyWithHint "Charlie" (PartyIdHint "Charlie")
  userAdmin <- allocatePartyWithHint "UserAdmin" (PartyIdHint "UserAdmin") 

  aliceIssuer <- submit userAdmin do 
    createCmd Issuer 
      with 
        userAdmin = userAdmin 
        issuer = alice 

  originalToken <- submit alice do 
    exerciseCmd aliceIssuer MintToken 
      with 
        description = "Cat Pic 1"
        initialPrice = 100.00
        currency = "USD" 
        royaltyRate = 0.05

  bobOffer <- submit alice do 
    exerciseCmd originalToken Offer 
      with 
        newOwner = bob 
        price = 200.00 

  bobRequest <- submit bob do 
    createCmd OwnerRequest 
      with 
        userAdmin = userAdmin 
        owner = bob 
        reason = "I've got connections"

  bobOwner <- submit userAdmin do 
    exerciseCmd bobRequest GrantOwnerRights

  charlieRequest <- submit charlie do 
    createCmd OwnerRequest
      with 
        userAdmin = userAdmin 
        owner = charlie 
        reason = "FOMO" 

  charlieOwner <- submit userAdmin do 
    exerciseCmd charlieRequest GrantOwnerRights

  (bobToken, _, _) <- submit bob do 
    exerciseCmd bobOwner AcceptTokenAsNewOwner
      with 
        offerId = bobOffer

  charlieOffer <- submit bob do 
    exerciseCmd bobToken Offer 
      with 
        newOwner = charlie 
        price = 300.00 

  submit charlie do 
    exerciseCmd charlieOwner AcceptTokenAsNewOwner
      with 
        offerId = charlieOffer

  return ()
2

It’s hard to be 100% sure without access to your Issuer template definition, but the error message seems to imply that the Issuer contract you’re creating with:

  aliceIssuer <- submit userAdmin do 
    createCmd Issuer 
      with 
        userAdmin = userAdmin 
        issuer = alice

is only visible to UserAdmin, and not to Alice. In order for Alice to be able to do anything with it, you’ll need to add the issuer field of Issuer to either the signatory or, more likely, the observer property of Issuer.

This is possibly a side-effect of the controller can to choice syntax change: with the controller can style, the controller is implicitly added to observer.

3

Here is the issuer code

template Issuer     
  with
    userAdmin: Party     
    issuer: Party        
  where
    signatory userAdmin  


    nonconsuming choice MintToken: ContractId Token   
        with
          description: Text
          initialPrice: Decimal
          currency: Text
          royaltyRate: Decimal
        
        
        controller issuer

        do
          issued <- getTime
          create Token
            with
              lastPrice = initialPrice
              owner = issuer
              ..  
    
    choice   

      RevokeIssuer: ()

      controller userAdmin
        do return ()

and script error

Script execution failed on commit at Main:25:20:
  Attempt to fetch or exercise a contract not visible to the reading parties.
  Contract:  #0:0 (UserAdmin:Issuer)
  actAs: 'Alice'
  readAs:
  Disclosed to: 'UserAdmin'

Ledger time: 1970-01-01T00:00:00Z

Partial transaction:

Committed transactions: 
  TX 0 1970-01-01T00:00:00Z (Main:19:18)
  #0:0
  │   known to (since): 'UserAdmin' (0)
  └─> create UserAdmin:Issuer
      with
        userAdmin = 'UserAdmin'; issuer = 'Alice'
4

Right, so this can indeed be fixed by adding issuer as an observer; specifically:

module Main where

import Daml.Script

template Token
  with
    lastPrice: Decimal
    owner: Party
  where
    signatory owner

template Issuer     
  with
    userAdmin: Party
    issuer: Party
  where
    signatory userAdmin  
    observer issuer -- This is the line that makes it work
    nonconsuming choice MintToken: ContractId Token   
        with
          description: Text
          initialPrice: Decimal
          currency: Text
          royaltyRate: Decimal
        controller issuer
        do
          issued <- getTime
          create Token
            with
              lastPrice = initialPrice
              owner = issuer
              ..
    
    choice RevokeIssuer: ()
      controller userAdmin
      do return ()

setup : Script ()
setup = script do
-- user_setup_begin
  alice <- allocatePartyWithHint "Alice" (PartyIdHint "Alice")
  bob <- allocatePartyWithHint "Bob" (PartyIdHint "Bob")
  charlie <- allocatePartyWithHint "Charlie" (PartyIdHint "Charlie")
  userAdmin <- allocatePartyWithHint "UserAdmin" (PartyIdHint "UserAdmin") 

  aliceIssuer <- submit userAdmin do 
    createCmd Issuer 
      with 
        userAdmin = userAdmin 
        issuer = alice 

  originalToken <- submit alice do 
    exerciseCmd aliceIssuer MintToken 
      with 
        description = "Cat Pic 1"
        initialPrice = 100.00
        currency = "USD" 
        royaltyRate = 0.05
  pure ()
5

thanks
@Gary_Verhaegen can you tell me how can I find a DAML developer who can help us in our project as a paid developer…

6

Hi Nimra,

Can you please share your official mail id and accordingly we can connect with you to
discuss regarding the same.

Or you can drop a mail to sales@digitalasset.com

Regards,
Nava

7

@Navajith_Mohanan
18094198-084@uog.edu.pk
official email id

8

@Navajith_Mohanan Hey
I have share my email id and also drop a mail to sales@digitalasset.com
but didn’t get any response yet.

I am waiting for your response.

Regards
Nimrah Perveen

9

Hey Nimrah - I have just replied to your email