1 Introduction
In this document, we explain how to solve the most common consistency errors that can occur when configuring microflows in Mendix Studio. For more information on microflows, see Microflows.
An example of a consistency error is when you set a drag and drop a Create Object activity to the microflow, but do not specify what entity should be used as a data source to create the object.
This document does not describe all the errors, as there are a lot of errors that can occur, some of which are simple and do not need extra explanation, others are rare and/or heavily dependent on a use-case.
Some errors have error codes and if these errors are described in documentation, Studio has a clickable link to the corresponding document. Others do not have an error code, in this case, you can manually search whether a particular error is described in documentation (you can search by a message you see in the Checks panel).
2 Properties Not Set Consistency Errors
Many errors occur if you do not set properties (for example, a data source) for an element or an activity. The most common errors of this type are described in the table below:
| Error Code | Text in the Checks Panel | Element/ Activity | Cause of an Error | Way to Fix |
|---|---|---|---|---|
| CE0080 | ‘Condition’ is required. You can set it in properties. | Decision | You have added an decision to your microflow, but did not specify any condition for it. | Configure condition for the decision: open Properties > Data Source and specify Condition. |
| CE0079 | The ‘true’ case should be configured in properties for an outgoing flow. | Decision | You have added an decision to your microflow, and set an attribute of the Boolean type as a Condition but did not configure a case for the true value. | Open the properties of the decision, in the Cases option click New Case > Edit. The Decision Value properties will open, in the Value option select True. |
| CE0079 | The ‘false’ case should be configured in properties for an outgoing flow. | Decision | You have added an decision to your microflow, and set an attribute of the Boolean type as a Condition but did not configure a case for the false value. | Open the properties of the decision, in the Cases option click New Case > Edit. The Decision Value properties will open, in the Value option select False. |
| CE0105 | Decision cannot be the last object of a flow, it should end with an end event. | Decision | The decision does not have any flows succeeding it. | Add an outgoing flow after the decision with another activity or an end event. |
| CE0099 | A ‘Loop Over’ list is required. You can set it in properties. | Loop | You have added a loop to your microflow but did not specify a list to loop over. | Open the properties of the loop and set a list in the Loop Over property. |
| CE0101 | ‘Loop Object Name’ is required. You can set it in properties. | Loop | You have added a loop to your microflow but did not specify the variable name. | Open the properties of the loop and specify the Loop Variable Name. |
| CE0119 | An entity is required for ‘Object’ or ‘List’ data type. You can set it in properties. | Parameter | You have added a parameter of Object or List data type, but did not specify an entity for it. | Open the properties of the parameter > the Data Source section, and set Entity. |
| CE0012 | A list is required. You can set it in properties. | Aggregate List | You have added an Aggregate List activity to your microflow but did not select a list variable for it. | Open the properties of Aggregate List and select a list in Data Source > List. |
| CE0015 | An attribute is required for the selected ‘Operation’. You can set it in properties. | Aggregate List: Calculate Sum, Calculate Average, Calculate Maximum, Calculate Minimum operations | You have added an Aggregate List activity to your microflow and set Operation in the properties to Calculate Sum, Calculate Average, Calculate Maximum, Calculate Minimum, but did not select an attribute which the Operation would be applied to. | Open the properties of Aggregate List and select an attribute in Behavior > Attribute, or change Operation to Count. |
| CE0031 | An object is required. You can set it in properties. | Change Object | You have added a Change Object activity to your microflow but did not specify a variable for it. | Open Properties of Change Object > Data Source and set Variable. |
| CE0040 | An object or a list is required. You can set it in properties. | Commit | You have added a Commit activity to your microflow but did not select a an object or a variable for it. | Open the properties of Commit and select an object or a list in Data Source > Object or List. |
| CE0050 | Create object action must define a data type. | Create Object | You have added a Create Object activity to your microflow but did not select an entity for it. | Open the properties of Create Object and set an entity in Data Source > Entity. |
| CE6005 | An entity is required. You can set it in properties. | Create Object | You have added a Create Object activity to your microflow but did not specify a entity for it. | Open the properties of Create Object and specify an entity in Data Source > Entity. |
| CE0057 | An object or a list is required. You can set it in properties. | Delete Object | You have added a Delete Object activity to your microflow but did not select a variable for it. | Open the properties of Delete Object and set a variable in Data Source > Variable. |
| CE0136 | Retrieve object must specify an entity. You can set it in properties. | Retrieve | The reasons of this error can be the following ones:
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Open the properties of Retrieve and set an association (for Source > By Association ) or an entity (for Source > From Database) in the Data Source section. |
| CE0018 | An association is required for the ‘By Association’ data source. You can set it in properties. | Retrieve | You have added a Retrieve activity to your microflow and have set Source > By Association in the properties, but did not select an association itself. | Open the properties of Retrieve and set an association in Data Source. |
| CE0566 | Select a page for this action activity. | Show Page | You have added a Show Page activity to your microflow but did not specify a page to show. | Open the properties of Show Page and set a page in Data Source. |
| CE0037 | A variable is required. You can set it in properties. | Change Variable | You have added a Change Variable activity to your microflow but did not specify what variable to change. | Open the properties of Change Variable and set a variable in Data Source. |
| CE0038 | ‘Value’ is required. You can set it in properties. | Change Variable | You have added a Change Variable activity to your microflow but did not specify the new value for the changed variable. | Open the properties of Change Variable and set Value in Data Source. |
| CE0038 | ‘Value’ is required. You can set it in properties. | Create Variable | You have added a Create Variable activity to your microflow but did not specify the initial value for the variable. | Open the properties of Create Variable and set Value in Data Source. |
3 Properties Set Incorrectly Consistency Errors
If you have not configured properties of an element or an activity correctly, you will get consistency errors. For example, you have set an attribute of the integer type for an decision, when only Boolean and enumeration types are allowed for it.
The most common errors of this type are described in the table below.
| Error Code | Text in the Checks Panel | Element/ Activity | Cause of an Error | Way to Fix |
|---|---|---|---|---|
| CE0078 | Condition should be of type Boolean or enumeration but is of type {type of condition}. | Decision | You have configured an invalid condition expression in the decision properties. The condition expression should return a Boolean or an enumeration. | Expression should return a Boolean or an enumeration: open the decision properties > Data Source > Condition, and select a variable or an attribute of Boolean or enumeration type. |
| Value must be of type {type of value}. | Decision | You have configured a condition for the decision which does not result in a Boolean or enumeration, so the selected split condition is invalid. | Open the decision properties > Data Source > Condition and configure a condition that results in a Boolean or enumeration. | |
| CE0108 | Variable {variable name} is defined but not in scope at this location. | Change Variable | You have added a Change Variable activity to the microflow before an activity that creates this variable. | Change the order of the activities in the microflow placing the activity that creates a variable first. Only after that you will be able to change it: add a Create Variable activity before Change Variable. |
| CE0109 | Undefined variable {variable name} | Create Variable/ Change Variable | A variable that is not available anymore is used in the microflow. You have deleted an activity that provided the variable. Parameter, Create Object, or Create Variable can provide variables for the microflow, and that variable was used for Create Variable or Change Variable activities. | Add an activity that will provide the microflow with a variable that is missing, or select another variable for the Create Variable/ Change Variable activity in properties. |
| CE0161 | Error(s) in the filter conditions. Open ‘Filter’ of the Retrieve action and check the marked conditions | A filter of a Retrieve action | A filter condition is no longer valid. | Open properties of the Retrieve activity > Filter and check the conditions that are marked in red. |
4 Errors Connected with Studio Pro Settings
Some consistency errors may be connected with settings in Mendix Studio Pro. The most common errors of this type are described in the table below.
| Error Code | Text in the Checks Panel | Element/ Activity | Cause of an Error | Way to Fix |
|---|---|---|---|---|
| The selected microflow {name of the microflow} no longer exists. | Microflow | You have deleted a microflow that is selected in Studio Pro > app Settings > Runtime > After startup or Before shutdown options. For more information on After startup /Before shutdown microflows, see section 7 After-Startup and Before-Shutdown Microflows in Clustered Mendix Runtime in the Runtime category. | There two ways to fix the error:
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| CE0142 | After startup microflow should return a Boolean. | Microflow | This microflow is selected in Studio Pro > Project Settings > Runtime > After startup or Before shutdown options, and should return a Boolean. For more information on After startup /Before shutdown microflows, see section 7 After-Startup and Before-Shutdown Microflows in Clustered Mendix Runtime in Runtime category. | Open the properties of the microflow’s end event > the Return Value section, select Value option > set Data Type to Boolean and configure the Value. |