The error indicates that NaviServer is trying to load Tcl's libthread, but that the loaded .so file wasn’t compiled with the AOLserver/NaviServer compile flag. When you use install-ns (always use the latest version), this flag is set automatically.
Please verify which Tcl version you are using. To help diagnose the issue, it’s most useful if you post the output of the "SETTINGS" section from install-ns.
It’s also possible that you have multiple versions of libthread installed on your system, and NaviServer is picking up the wrong binary (.so file). The configuration file in use determines which .so file is selected. For example, you can run the following command to list the available thread libraries.
ls -ltr `find /usr/local/ns/lib/thread* -type f`
changed ...
If you continue to experience issues, we recommend starting with the unmodified configuration file to verify that the base setup works correctly before applying any custom modifications.
All the best
-g