Failed to set property "%1!s!" on "%2!s!". The property could not be set for an unknown reason.

Community Notes

Examples of this error can be seen when calling SetComponentProperty method of CManagedComponentWrapper, such as when building the Data Flow programmatically. Causes for this are usually simple mistakes when programming for example:

• Property name passed into SetComponentProperty incorrect.
• Component is incorrect. Check the Count of IDTSComponentMetaData90.CustomPropertyCollection.
• Forgot to call ProvideComponentProperties, which will create the properties you intend to set. Until this is called the IDTSComponentMetaData90.CustomPropertyCollection will be empty.
• The property value is not valid, the component may validate the value and reject it. This can be difficult to spot depending on how the packages is being built. Programmatically you may just get a COMException without any real explanation, but the designer may give a full message.

 ...
 IDTSComponentMetaData90 component = dataFlow.ComponentMetaDataCollection.New();
 component.ComponentClassID = "...";
  CManagedComponentWrapper instance = component.Instantiate();
 instance.ProvideComponentProperties();
 instance.SetComponentProperty("Rows", rows);
 ...

 Could not set the property value:
 Error at DFT Fuzzy Lookup [FZL Fuzzy Lookup [1015]]: 
   The MinSimilarity threshold property on the Fuzzy Lookup transformation must be 
   a value greater than or equal to 0.0 but less than 1.0.

ComponentErrorCodes