It is often possible to run an older Hub (hub.exe) together with applications compiled wth WebHub components that are "older."

The features that probably will not work are those involving cover pages (web pages which display during error conditions, such as when the application is not running).

To make this work, you must coordinate tell the old AND new systems where the session files are located, pointing both to the same location.

For New WebHub

Use ZMAdmin to review the path to the session VAR files. Look under: WebHub Configuration > Connectivity Layer > Hub > Sessions (on the left pane), and set Session VAR Folder (on the right pane). There are some other characteristics of the session file specified there as well, such as the number of digits, and so on. You may customize those, as long as you make the same customizations for your old WebHub apps.

For Old WebHub

Details vary, but here is the best way to figure out what is controlling the settings.

1. Look in the registry for the key with the HREFTools\WebHub settings. The registry location should be [HKEY_CURRENT_USER\Software\HREF Tools\WebHub]. A string value in that section should point to a hubmain.ini file, or possibly a hub.ini file, or even a customized filespec.
2. Open the referenced file in Notepad. It should contain the session folder definition --- or --- it might point to a file which will.

After changing configuration

If you found a conflict in the paths used, stop all WebHub software and move the VAR files to one directory (or directory tree if you are using sub-folders).

Finally, reboot the server -- or -- less drastically, you can restart IIS (or just recycle the relevant AppPools), restart the Hub service, and restart all of your WebHub apps.