this sometimes happens if there has been a budged installation, or if a removal has been incorrect.
Search your USERDIR for the 'dot' file
.lmmsrc.xml
and move that to a different folder
Now you could try to start LMMS, and that would (i hope) go perfectly, but since you may have incomplete or bad installation on disk, i would run through a full de-install, delete the old install-pack, and download a fresh new 1.1.3
Then install
If it fails, then post again, but this time:
post your:
* OS
* lmms vers
* hardware specification (ram & soundcard is the most imortant)