Warning: Error compiling .temp/styles/styles.less Use --force to continue

[bl4ckc00k1e]

When i run "grunt build"

Running "less" task

Running "less:app" (less) task
Verifying property less.app exists in config...OK
Files: .temp/styles/styles.less -> .temp/styles/styles.css
Options: report="min", banner=""
Reading .temp/styles/styles.less...OK
FileError: 'bootstrap.less' wasn't found in .temp/styles/styles.less on line 1, column 1:
1 @import 'bootstrap.less';
2 @import (inline) 'ladda-themeless.css';
Warning: Error compiling .temp/styles/styles.less Use --force to continue.

Aborted due to warnings.

I try with --force, but the nginx or the grunt show me in blank the website...

grunt bower:install

Fatal error: Arguments to path.join must be strings

My system an versions:
Linux version 3.13.0-37-generic (buildd@roseapple) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #64-Ubuntu SMP Mon Sep 22 21:30:01 UTC 2014

$ grunt --version
grunt-cli v0.1.13
grunt v0.4.5
$ npm -v
1.4.28
$ bower -v
1.3.12
$ node -v
v0.10.32

Thanks for the help

[mrpollo]

@bl4ckc00k1e can you try bower install before grunt bower:install and let me know what that works?