value enablePlugins is not a member of sbt.Project

Today I was setting up a couple of projects. One was a simple model library, the next an Akka application, and the last a Play app that started spitting up errors after I had finished setting up the initial project structure.

[info] Loading project definition from /path/project
[info] Compiling 1 Scala source to /path/project/target/scala-2.10/sbt-0.13/classes...
[error] bad symbolic reference. A signature in Play.class refers to type AutoPlugin
[error] in package sbt which is not available.
[error] It may be completely missing from the current classpath, or the version on
[error] the classpath might be incompatible with the version used when compiling Play.class.
[error] /path/project/Build.scala:21: value enablePlugins is not a member of sbt.Project
[error] possible cause: maybe a semicolon is missing before `value enablePlugins'?
[error]     .enablePlugins(play.PlayScala)
[error]      ^
[error] two errors found
[error] (compile:compile) Compilation failed
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? q

I did a little searching only but couldn't find anything that seemed to match my case. After meticulously comparing the few files in the project to the examples on in the documentation, I found the upgrade guide, and noticed that the sbt version was different than what my build.properties file stated.

So I opened up build.properties and noted the version I originally had

sbt-version=0.13.0

and replaced it with the one in the migration docs:

sbt.version=0.13.5 

Hopefully this helps anyone else running into similar issues.