The error originates from the C source for lfe
(line 214). According to the source:
i
is the number of iterations you've gone through to try to converge on a solution (so in the OP's case, 6.35 million...)
c
is your convergence rate for a given iteration
d
is delta
t
is your target
The message itself appears to be a primitive progress bar to keep you apprised of how many iterations you've done and the ETA of a result. In this case, it appears you are having troubles converging on a solution. The reason for why this is is be a better question for Cross Validated and you would be best served by providing them with a minimal reproducible example.
A good start on your own would be to carefully read the lfe
documentation and vignettes. There is an entire vignette about speed that suggests other functions you may want to try (apart from felm
) if your procedure is going slowly or not converging.