[ns] Please help me with this error

[N_F]

Hi all,

I have  an agent implemented in ns which used to work properly before, but
now when I am trying to run different tcl files I m getting the same error
as below:
ns:
[code omitted because of length]
: invalid command name "Agent/hoperaa"
    while executing
"Agent/hoperaa set packetSize_ 40"

Does anyone have an idea about this error?

Thanks in advance,
/Negin