optim function in r returning a list with an error message

Question

I ran the optim function on a function that has 3 numeric parameters.

It did return what looks to be the correct values. However, in the message element of the returned list, I got this message:

$par
[1] 0.8974235 9.1095283 0.9110162

$value
[1] -614452.9

$counts
function gradient 
      60       60 

$convergence
[1] 52

$message
[1] "ERROR: ABNORMAL_TERMINATION_IN_LNSRCH"

What does that mean? How can it be remedied?