"Unable to prepare context" during creation of instance

[lukastocker]

While creating a new instance I got following error message:

Install base image ...

In SymfonyShell.php line 22:
                                                                                                                           
  The command "'docker' 'build' '-t' 'doil/base_global:stable' '/usr/local/share/doil/templates/base/Dockerfile'" failed.  
                                                                                                                           
  Exit Code: 1(General error)                                                                                              
                                                                                                                           
  Working directory: /home/luka/cate-projects                                                                              
                                                                                                                           
  Output:                                                                                                                  
  ================                                                                                                         
                                                                                                                           
                                                                                                                           
  Error Output:                                                                                                            
  ================                                                                                                         
  unable to prepare context: context must be a directory: /usr/local/share/doil/templates/base/Dockerfile