Model backward / forward compatibility

Applies To 
Product(s): WaterGEMS, WaterCAD, HAMMER, StormCAD, SewerCAD, CivilStorm, SewerGEMS, PondPack, FlowMaster, CulvertMaster
Version(s): All
Area:  Modeling
Original Author: Dan Iannicelli, Bentley Technical Support Group


Can I open a model saved in an older version? (is the software backward compatible?)

How can I send my model to a user who has an older version? Can it be "saved down"? The following error may occur when attempting to open a file saved in a newer version (or one of the errors in this article):

"The model you are trying to open was saved in a newer version and cannot be opened in this version."

Solution - Opening models from older versions

Generally speaking the OpenFlows products are backward compatible. Meaning, you can expect to be able to open a model file that was last saved in an older version. For some products, you may need to make a different selection for the "files of type" dropdown in the file open dialog, while most versions will simply open the older model directly.

Note: see the following article for opening older WaterCAD, WaterGEMS or Cybernet models with a .WCD file extension: Opening old WaterCAD or WaterGEMS WCD model files and preserving presentation settings

A note on OpenFlows product Database Format (Schema)

It is important to note that the "water" products (WaterCAD, WaterGEMS and HAMMER) share the same model database format. So, a model saved in WaterCAD can be opened in WaterGEMS or HAMMER and vice-versa, as long as the version that the model was saved in is less than or equal to the version of the water product that you are opening it with.

The same is true for the four "storm/sewer" products: SewerGEMS, CivilStorm, StormCAD and SewerCAD. 

Solution - Opening models from newer versions

Currently, a model cannot be saved 'down' and most versions are not forward compatible. Meaning, you generally are not able to open a model that is saved in a newer (forward) version. For example, if you've created and saved a model in WaterGEMS CONNECT Edition Update 3, a user with an earlier version (such as Update 2) will not be able to open it.

  • Model files within a set of major releases will be forward compatible (*). e.g. version 10.03.00.XX will be able to open files saved in 10.03.01.XX
  • Between major versions model files will generally not be forward compatible. e.g. a files saved in version 10.03.xx cannot be opened in 10.02.xx
    • Exception: Files saved in version 10.04.xx can be opened in 10.03.xx.

(*) Note that settings introduced in a newer minor version will be ignored by the older version (e.g. 10.03.00 will ignore any new settings introduced in 10.03.01).

A "major" release has a version number whose second group of digits increase, whereas a "minor" release only changes the number in the last group of digits. For example a model saved in version can be opened in, but not in version

New major versions of the programs have introduced many new element types and features, which could not be interpreted by an older version. Another reason is that the structure of the database files used to store model data (the 'schema') changes between major versions to accommodate improvements and new features. The older versions cannot interpret the new database format.

To find the version that the model file was saved in, see: How to find the version a model was created in and last saved in

Below are the options available:

Option 1: Upgrade

The recommended solution is to upgrade to the latest version of the software, or at least the version used to modify the model you want to open.

Downloading OpenFlows / Hydraulics and Hydrology Software

Option 2: Export to EPANET (Water) or EPA SWMM / LandXML (Storm and Sewer)

If the user is not able to upgrade to your version, the best workaround for the Water products (HAMMER, WaterCAD, & WaterGEMS) would be to export the model to the standard EPANET format (File > Export > EPANET). This format can be opened in most older versions (File > Import > EPANET). For example in older v8i versions, you can import EPANET via File > Import > Network. Note that there are limitations with this method such as only being able to export one scenario, and other items described in this wiki article .

The best workaround for SewerGEMS and CivilStorm would be to export the model to the EPA SWMM format (File > Export > SWMM v5). After that the SWMM file can then be opened by most older version of the software (File > Import > SWMM V5). As with the EPANET for the water products, you may also run into some limitations or have the potential to lose some information in the process of the export/import. In SewerCAD and StormCAD, you can export the model to the LandXML format (File > Export > LandXML) and import the LandXML file into the older version of SewerCAD or StormCAD.

Option 3: Export to Shapefiles

Another workaround would be to export all elements in your model to shapefiles and then import those shapefiles with the older version of the software using ModelBuilder. 

The first thing you need to do if you're using this method would be to make sure all your FlexTables have all the information you input for the properties of each element and then export each element to Shapefiles. Export your elements to Shapefiles is described in the following wiki:

Converting your model elements to Shapefiles

After you do this you would need to use the ModelBuilder tool in the older version of the software (Tools > ModelBuilder) to import all those elements back in. Using ModelBuilder to construct a network is described in this wiki found below and there is also information in our help documentation on how to use ModelBuilder:

Building and updating a model using ModelBuilder

This method can take some time to work through. It will assure the data is imported accurately. However, each scenario will need to be done separately.


In case of Flowmaster, files saved in higher versions like cannot be opened in lower version since the database formats are different, Newer versions support .sqlite database whereas older versions support .mdb database format, so to open file saved in higher version into lower version, .mdb file is required. But once model is opened in higher version .sqlite file is created. 

See Also

"Unsupported dataset type schema" error or "Object reference" error when opening a model

"Unexpected drawing version..." error when opening model