What I am doing with Toolkit 1.10.5 ? Create a new project ? Copy and paste from excel 145 groups ? Add some levels to first group ? Save project so I can get back to play with the number of groups in project ? Delete one of the levels Crush Have discovered by trial and error that number of groups seems to go with size of the machine i.e. on laptop the magic number is less than the tower. With 145 groups never hear from Toolkit again ? need the task manger to kill it Restart Toolkit ? delete project and reload from backup Delete any group except first now 144 Delete level And all works ok Delete project and reload Add a new group ? now got 146 Delete level Crush Tech support - confirm and should be working on it No that's fine Dave, did exactly what you said and 'bam', up came all these nasty unexpected errors. Have notified the software engineers, and will await their response and let you know. Have created a case with you #00005371