Here you will find an explanation and best practices for solving Data inconsistency related synchronization errors.  

Category: Inconsistent Data

Inconsistent data refers to data that contains discrepancies or errors within a dataset. These inconsistencies can arise for various reasons and can make the data unreliable or difficult to work with.

Duplicated data in an iModel

Duplicated data can be introduced in different scenarios and can cause duplicated data to appear in the iModel, which is not desired. 

 Error: Dgn_0199

 Error message: "Duplicate models found MasterSubject:<File name> MissingInputFile: <File path>.

Issue:
Visual fidelity issues in the model such as duplicated graphical information and properties. 

Cause:

• Multiple copies of the same reference file are used in different master files connections.
• Multiple copies of the same file are configured in different connections.
• If using ProjectShare, a folder name change can lead to the creation of duplicates because the file will be identified with a different GUID and is recognized as a duplicate file by synchronization.
• If using ProjectShare, moving the master file or references to a different folder causes file GUID changes and is recognized as a duplicate file by synchronization.
  
  

Solution:
To avoid duplicate data processing into the iModel, please ensure that:

• Only one version of the file is mapped into the Model.
• Multiple connector types are not used to synchronize the same file.
• In case multiple versions of the same file have been mapped and processed to the model, please unmap the duplicated files from the connection by selecting the option to remove changes from the iModel and reprocess the files.
• If duplication was introduced after moving files to a different folder in ProjectShare, to resolve the duplicate issues duplicate files need to be unmapped with all changes, mapped again and changes resynchronized. 
• Update the design file to remove duplicates and resynchronize the files.For other cases, please contact Bentley support to further diagnose this kind of error: https://apps.bentley.com/srmanager/digitaltwins

 Error: Dgn_0066, DgnV8_0142, DgnV8_0141

 Error message: File <File name> has <File path> as its documentId from the dgn file. However, the attachment data from the data source is <File ID>.

Issue:
Visual fidelity issues such as graphical and properties duplication.

Cause:
References ID had changed due to reference file migration to a different data source.

Solution:
Run a Scan References on the master file and then restart the synchronization. If the duplicate issues cannot be solved, please contact Bentley support to further diagnose this kind of error: https://bentleysystems.service-now.com/csp
Read more about why reference scanning is important. 

Alert messages 

The purpose of an alert message is to convey important information. 

Error: ifc_0020, Ifc_0021

 Error message: "An element in <File name> is re-using GlobalID <GUID>. The last seen element with this GlobalID will be present in the iModel."

Issue:

Visual fidelity issues in iModel such as missing element/s.

Cause:

• The source application generated the IFC file that has an element(s) with the same Global ID.

• Elements in the IFC file that have the same Global ID and other elements (s) with identical Global ID were skipped. The iModel Connector for IFC only imports the first object with the Global ID and ignores the rest that uses the same Global ID during an individual synchronization. In the case where there are duplicate instances of the same Global ID, there will be missing elements in the iModel.

Solution:

• Fix the duplicate Global Ids in the IFC File.  Since IFC is an open standard for the exchange of building information models (BIM) data, it cannot be updated directly. Updating an IFC file usually involves making changes that will result in the removal of duplicate Global IDs from the underlying building information model in the source application, and then re-exporting the updated model to a new IFC file. 

• Once a new IFC has been generated resynchronize the IFC file to the iModel. This should solve any issues with the missing element(s).

• Contact Bentley Support for assistance if these issues cannot be solved.

Warning: Ifc_0042

 Warning message: "Multiple datatypes 'DataTypeName' are defined for property 'Property Name' in the property set 'Property Set Name' resulting in data loss. This inconsistency needs to be corrected by the source application for this property to be consistently synchronized."

Issue:

Data loss is observed for the element with the problematic property in the iModel (e.g. Property 'NEL_Diameter' shows an empty value in the properties section in the iModel).

Cause:

An element in the iModel has a problematic property that is inconsistently defined by different datatypes in multiple property sets (e.g. property for one property set is defined as 'IfcText' and in other property sets it is defined as 'IfcReal') which resulted in data loss. The inconsistency causes the issue. 

Solution:

• The inconsistency of datatypes for the problematic property should be fixed in the IFC File. Since IFC is an open standard for the exchange of building information models (BIM) data, it cannot be updated directly. The inconsistency in the IFC file should be corrected in the design application so that there will be no missing data for the property in the iModel. Once the IFC file has been corrected and generated from the design application, resynchronize the IFC file to the iModel. This should solve any issues with the missing data for the problematic property.
• Contact Bentley Support for assistance if these issues cannot be solved..

Error: Ifc_0048

 Error message: "Units of type MASSDENSITYUNIT not defined"

Issue:

Missing information in the IFC file MASS DENSITY UNIT in the iModel viewer.

Cause:
MASS DENSITY UNIT values were incorrectly exported to the IFC file from the design application and can not be converted to the iModel 

Solution:
Since IFC is an open standard for the exchange of building information models (BIM) data and not a design file format, it cannot be updated directly. Updating the units in the IFC file will typically require making the appropriate changes in the design application so that the MASS DENSITY UNIT will be updated the next time an IFC file is generated from the design application. Once the unit is correctly reflected in the IFC file, it can be resynchronized into the iModel.