Clearing Warning Messages in Mendix

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This how-to explains how to eliminate design time warnings.  While these warnings will not cause the application to break, it is important to fix them to keep a clean project.

1. Viewing Warnings

Warnings can be seen in the ‘Error List’ tab.  By default, this is shown in the bottom of the modeler.  Note that the ‘Warnings’ box must be selected for them to display.

If this tab is not visible, it can be shown via the ‘View’ menu, by selecting the ‘Error List’ option.

The warning can be double clicked or right-clicked to get more information.

2. Common Warnings

  • This will not affect the project in this version of the modeler, but may cause problems upgrading.  In this example, the pop-up layout must be adjusted to no longer use the main placeholder.
  • Once the microflow has split due to an error, the flow that executes due to the error should not merge with the flow that executes when no error occurred. 
  • The security for the entity ‘System.FileDocument’ has a default setting, which can cause security loopholes.  This warning suggests creating specialized entities to eliminate such scenarios. 
  • Data source microflows should not have an effect on the client.  This microflow likely has a ‘Show Message’  or ‘Show Page’ activity which should be removed. 
  • The specified caption or title is empty.  This should be populated, so the page will be understood.
  • Similar to the ‘Empty Caption’ above, this should be populated to ensure the page will be understood.
  • The selected progress message is empty, but should be populated.
  • This context is read only, but there are events set on the field - either on-change, on-leave, or on-enter.  
  • There is no need for a microflow which is not accessed through navigation, page, or published app service to have security roles allowed.  This can lead to a security problem, and the assigned roles should be removed.  
  • This microflow performs no functionality.  It should either be removed or functionality should be added. 
  • The module role cannot be used by any users.  This module role should either be removed or assigned to a user role, so the proper security is enforced.
  • When using a form for reference selector, the constraint should be set on the reference selector  - not the form
  • On a page, a field can be set to required.  When the field is set to required, the ‘Required Message’ should be set.  Here, either the ‘Required Message’ must be set, or the field must not be required. 
  • This is similar to the previous warning.  If the field is not required, the ‘Required Message’ should be empty.  If the ‘Required Message’ was set with the intention of making the field required, the field should be made required. 
  • Edit published web service to include a proper namespace
  • There are multiple potential causes here.  The solution involves removing the variable from the microflow.  This could mean deleting the retrieve activity or electing to not use the return value of a microflow call.

Several warnings relate to improper security.  To read more on this, please view the documentation here.