Most instruments by default have a click associated with lack of envelope. Here is the documentation entry:
https://docs.lmms.io/user-manual/gettin ... -envelopes
Don't forget to turn AMT up to 100, or click the envelope. This is how the volume envelope is turned on.
You may also want to increase the "Length" knob on the main window of kicker synthesizer.
It's not a bug, it's how it's supposed to work. It's quite annoying, but we can't think of a more sensible solution everyone will agree on (a default envelope with mild attack and release, however, is being thought of and appears to have been in progress multiple times.)
That being said, I agree with Fedyarov. There are efficient ways to phrase a request for help that don't involve repeated cursing and commanding tones. Also that the Hydrogen samples are pretty good, because then you don't need to synthesize them in kicker, but you'll need some release even there.