Modern browsers block ActiveX and NPAPI plugins. You may need to use Pale Moon or an older Firefox/IE in a VM.
If you have found an Axis 2400 using this query (or found one on your own network), immediate action is required to secure the device: Modern browsers block ActiveX and NPAPI plugins
Use param.cgi (requires auth):
http://root:pass@192.168.0.90/axis-cgi/param.cgi?action=update&root.PreBuffer=75