Version Differences for X cannot be cast to Y

Line 1:
    + <pre>X cannot be cast to Y</pre>  
    + <pre>com.urbancode.anthill3.domain.source.plugin.PluginSourceConfig cannot be cast to  
    + com.urbancode.anthill3.domain.source.svn.SVNSourceConfig</pre>  
       
    + = Explanation =  
       
    + This error will occur when steps of one SCM type are being configured to mix with steps of a different SCM type. Since a source config can only have one type, this will cause inconsistencies and errors within anthill.  
       
    + = Remedy =  
       
    + Remove the erroneous mismatched SCM type steps/workflows/etc. or convert the existing to match the source SCM type.  
       
    + = Error Examples =  
       
    + == Using Plugin Steps for AccuRev Legacy Steps ==  
    + <pre>ERROR - com.urbancode.anthill3.domain.source.plugin.PluginSourceConfig cannot be cast to  
    + com.urbancode.anthill3.domain.source.accurev.newworkspace.AccurevSourceConfig</pre>