Problem

The program hangs when attempting to open an existing model that was last saved in an older version.

Or

The program hands when attempting to switch to another scenario.

Solution

First, make sure you have the latest version of the software, as well as the latest update for it. See: Downloading OpenFlows | Hydraulics and Hydrology Software

If that doesn't help, please try the following.

1. Compact the database file. To do this, close the model, but leave the program open. Go to File > Database Utilities > Compact Database (or from the Tools menu, in older versions). Select the Database file and choose the option to purge the model to save space.

2. If compacting the database doesn't help, try moving the main model files (.wtg and .wtg.sqlite / .stsw and .stsw.sqlite, for example) to a new folder location. Then open the model from the new location. If this works, try copying over the .DWH file which will restore any background files.

3. If this doesn't help, try importing the database file. From the File Open Dialog, choose "database files" from the "files of type" dropdown and select your model database file (SQLITE for the latest versions).

4. If the above does not help, try updating your video card drivers. See: Updating video drivers and troubleshooting video hardware issues