You can get this error when you try to view in-progress frames with imf_disp.
To get around this error, try unsetting the MI_ENABLE_PIPE_MODE environment variable in setenv.bat.
By default, MI_ENABLE_PIPE_MODE is set to 1. To unset the variable, just delete the “1” so there is no value after the equal sign (=).
rem Render variables set MI_ENABLE_PIPE_MODE=
MI_ENABLE_PIPE_MODE is actually more for people who are having problemswith firewalls when running Softimage (such as constant “do you want to block/unblock” messages). It prevents mental ray from opening up tcp/ip sockets. Available on Windows only