Ran into this issue today while trying to run a program from IntelliJ and using SLF4J for logging. pom.xml looked like below:

<pre><dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.21</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <version>1.6.1</version>
</dependency>

</pre>

I was not creating any fat jar. The problem was that IntelliJ was not able to import the

slf4j-simple dependency. To check this goto View -> Tool Windows -> Maven Projects.
Saw red swiggly lines as described in http://stackoverflow.com/a/24892769/147530. Could not find artifact descriptor.
Solution:
Downloaded the file manually from https://mvnrepository.com/artifact/org.slf4j/slf4j-simple/1.6.1 and installed it manually by running:

mvn install:install-file -Dfile=/Users/siddjain/Downloads/slf4j-simple-1.6.1.jar -DgroupId=org.slf4j -DartifactId=slf4j-simple -Dversion=1.6.1 -Dpackaging=jar

Now did a reimport in IntelliJ and the error went away