With Visual Studio 2012 Update 2, Web Essentials 2.7.
Suppose there is an error in LESS. When saving the file, a message is shown in the preview pane. It reads...
/*
Compile Error.
See error list for details
*/
It does not matter, what kind of error is in the LESS. Any error is handled as above.
What can be done, so a detailed error message is given?
Are you using @import statments? If so, try switching to @import-once. That was my issue. The structure of my LESS directory calls for several "partials", many of which interact with the same base mixins or variable LESS file. To compile these files I had to add @import "mixins.less" to each of my partial files.
I then had a master LESS file which importing these partials, so if I were including 8 files, there would be those 8 @import statements as well as the @import statements in the partials. I think the LESS compiler couldn't handle the load, ran up to about 1.5 GB of memory and then broke. That was the message I was getting.