lmms: cannot connect to X server

LMMS 1.1.3 Copyright (c) 2004-2014 LMMS developers. usage: lmms [ -r <project file> ] [ options ] [ -u <in> <out> ] [ -d <in> ] [ -h ] [ <file to load> ] -r, --render <project file> render given project file -o, --output <file> render into <file> -f, --output-format <format> specify format of render-output where format is either 'wav' or 'ogg'. -s, --samplerate <samplerate> specify output samplerate in Hz range: 44100 (default) to 192000 -b, --bitrate <bitrate> specify output bitrate in kHz default: 160. -i, --interpolation <method> specify interpolation method possible values: - linear - sincfastest (default) - sincmedium - sincbest -x, --oversampling <value> specify oversampling possible values: 1, 2, 4, 8 default: 2 -u, --upgrade <in> [out] upgrade file <in> and save as <out> standard out is used if no output file is specifed -d, --dump <in> dump XML of compressed file <in> -v, --version show version information and exit. -h, --help show this usage information and exit.