Using Credentials Input requires manual node configuration every time?

I notice that the database nodes (reader, looping, etc) don't configure properly if credentials are supplied through a credentials flow-variable (not a workflow credential). Here is the test case.

  1. Create a new project. 
  2. Add a Credentials Input connected to a database reader node.
  3. Hardcode the database credentials in the credentials input and setup thedatabase reader to use the credentials from the previous node (also input a valid SQL query).
  4. Run the two-node workflow. it should work fine.

Now reset all the nodes, save the workflow and close it. When you re-open the workflow, you will get a warning message, "Error: Loading Model Settings Failed: Coding Issue: null" and you will not be able to run the workflow until you manually open the database node and click "Apply."

This prevents such workflows from being run from the command-line.

PS: I am aware that you can use workflow credentials to configure database nodes, however this will not work for me since these workflow credentials do not store the weakly encrypted password within the workflow itelf.

A lit bit of follow-up on my last post. I have made no progress getting the "Credential Input" method described above to work. Instead I have regressed to the old method of having one database conenctor connected to my 15 database nodes using a horrible mess of spagehtti node conenctors that make the workflow difficult to manage.

Doing this I leared that, if the node is previously configured to use the credentials supplied via flow variable and then you attach a database conenctor to override those credentials, the nodes still do not configure properly when the workflow is closed and then re-opened. You need to uncheck the credentials checkbox before attaching the database connector to get this to work.

This can be considered a bug in the database nodes. They do the settings validation a bit too early in the load process. (I can comment on the details if you like.)

I'll open a bug report. I need to check back with the maintainers of the DB nodes but I would expect that this will be fixed with the next feature release (early summer), if not earlier.


Reviewed this again with the team and we'll have a fix online by end of next week (version 3.1.2).

Thanks again,


Thanks! I'll check it out.


I am facing similar kind of problem in my custom node.

I have 3 settings model initialized in dialog. Two settings model get changed upon changing value of first setting model. When I click on apply * Validate settings * and *Load setting from validated * gets called and I am able to save the workflow.

However, when I open that workflow again, I get an error *Error: Loading Model Settings Failed: Coding Issue: null*.

Although after clicking on OK button, KNIME is openend. But there is a warning icon on m node. When I open the dialog all the settings that I have saved is saved there. But that warning icon is still there. When I click on apply again, then that icon goes.

So my question is can I avoid settings validation and load, when i open the saved worflow?

Because anyways when i click on apply settings are validated and loaded. So is there a need for validating it before opening the workflow?


Please reply.

I am stuck here for days.