anchor.diff:    java.lang.IllegalArgumentException: Unsupported class file major version 61
   ----  
   
  -then you've got a wrong java version.
  -dtcw tries to check the java version upfront by doing a  `java --version` but gradle sometimes picks up a different version.
  -In that case, please try to re-install a correct java version.
  +In this case, you've got an incompatible version of Java.
  +`dtcw` tries to check the Java version up front by running  `java --version`, but Gradle sometimes picks up a different version.
  +If you get a similar error, try reinstalling a compatible Java version.
  
positive.code: == Welcome!
  
  Nice to meet you.
  Glad that you want to learn more about how to use docToolchain.
  Let's start with the installation.
  
  The following steps are the same as described in the manual.
  Please follow them step by step.
  
  If you encounter problems, please create a github issue and the community will help you.
  
  include::../010_manual/20_install.adoc[tags=install]
  
  === Problems & Solutions
  
  ==== dtcw does not run
  
  When you get an error similiar to this one...
  
  [source]
  ----
  
negative.code: ./dtcw: line 1: `<!DOCTYPE html>'
  ----
  
  If you see that, it's likely that the wrapper didn't download correctly.
  You can that an HTML page was downloaded instead of the wrapper.
  Please try to redownload the wrapper.
  
  ==== Incompatible Java version
  
  You may see that docToolchain starts but crashes with a stacktrace that starts like this:
  
  [source]
  ----
  