I generally use RazorLame.

At the end of encoding it shows a bug with "At least one error occured" or something like this.

Are there better front-end programmes?

Is Version 1.1.5 too old? I can't find a new one...

Probably, it doesn't support the ReplayGain information LAME prints out at the end of the encoding process.
An error is also reported with LAME 3.90.3 modified to support APE files.

Try All2Lame or Multi Frontend. Both are excellent.

Regards,
Madrigal

There is also AdvaLAME Suite, based and improving on the last RazorLAME release.

What is the error-message?
Can be something wrong with your LAME command-line. What options did you use?

I only use --alt-preset standard or --alt-preset cbr 160.

Razor Lame says at least there was an unknown error message from the encoder.

I think Lame 3.96.1 sends a "news-message" to the frontend, but RazorLame can't do anything with this...

Bump

What does the log (View menu -> Last Log) say?
What is "news-message"?

Well, it's not a news message, it's a kind of report of the encoding results, I think, and RazorLame doesn't know this new feature of Lame 3.96.1 and above...

It is probably the replayGain information.

yes, it is! I checked the Log File by Editor, and there was something about the ReplayGain Information in the sector of bugs.

What's the purpose of ReplayGain Information? Has this feature an influence of quality, perfomance or decoding in players when I use RazorLame?

Here is info about a fix for this. Not officially released yet, though. But the replaygain info is ignored anyway.
. . . . . . . . . . . . . . . . . . . . . .
And here you find info about Replaygain. Foobar2000 and MP3Gain is two programs that implements this idea, to make different songs equally loud.