Merge PHP error

Hello, I have just setup myBB to try it out and transfer from my current forum software of SMF 2.0.15 ... But when going to the /merge to do a dry run. I get an error immediately.

This is with PHP 7.2.24
Merge version 1.8.11
myBB is

Warning [2] Use of undefined constant IN_MODULE - assumed 'IN_MODULE' (this will throw an Error in a future version of PHP) - Line: 134 - File: merge/resources/output.php PHP 7.2.24-0ubuntu0.18.04.1 (Linux)

File                                                      Line                                  Function
/merge/resources/class_error.php                60                                     errorHandler->error
/merge/resources/output.php                     134                                    debugErrorHandler->error
/merge/index.php                                   540                                     converterOutput->print_header

Warning [2] Use of undefined constant IN_MODULE - assumed 'IN_MODULE' (this will throw an Error in a future version of PHP) - Line: 753 - File: merge/resources/output.php PHP 7.2.24-0ubuntu0.18.04.1 (Linux)

File                                                     Line                                       Function
/merge/resources/class_error.php                60                                         errorHandler->error
/merge/resources/output.php                     753                                        debugErrorHandler->error
/merge/index.php                                   556                                        converterOutput->print_footer


I hope this helps in getting this to work without errors.