error Nintex workflows while initiating:Failed to start workflow. Login failed for user 'devadmin'

Does this error occur for every workflow or just this one? What actions have you used in the workflow?

If this is a general problem, can you please have a look at the ULS log for the time the workflow errored out and check if you find some more useful error message?

i am getting this for entore farm workflows. Below is the ULS entry that i see. Kindly help. this is the account: devadmin whihc i am using in connection string in Central admin . 

Nintex.Workflow.NWException: Could not retrieve workflow name for instance id. ---> System.Data.SqlClient.SqlException: Login failed for user 'devadmin'.
at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity.

Error establishing database connection. SQL Error: 18456.: System.Data.SqlClient.SqlException (0x80131904): Login failed for user 'devadmin'.
at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity,

@Manoj468 

I think this is related to the permissions on the Nintex databases. Try adding  WSS_Applications pool role for this account " devadmin " on all Nintex Databases. 

This post by Chad provides the answer. Please try the solution and let me know if you are having issues. 

https://community.nintex.com/t5/Nintex-for-SharePoint/Failed-to-start-workflow-The-EXECUTE-permission-was-denied-on/m-p/66095

@sunkars i have verified in SP Content databases : access looks fine as per your recomendation. 

i am attaching the screenshot from my Nintex DB server. Please have look . 

we are using devadmin user to connect to nintex database. i am able to login to Nintex DB server with this user: devadmin. also, i am able to make UDL connection from SP to Nintex DB server Via devadmin account.

But after logging into Nintex DB server-->under Nintex database , i dont see this account under security-->logins-- see the screenshot. 

can someone help me here

@Manoj468 

Go to Security-> Expand the users and select the database to the list with the db_writer and add the wss_applications pool role for "NintexAzureProd2_CopytoDev". 

Let us know if  you are still having issues