GAMMA Questions

Dear GAMMA Users,
I have been generating DEM using TerraSAR-X repeat-pass images following the tutorial 'README_TDX_demo_Etna'. In the line 230, the script notes that 'Important: the unwrapped phase needs to be carefully checked and if errors are observed these need to be fixed or masked'. I do not know how to check the unwrapped phase and how to define the errors. Is there a strict unwrapped phase value range limit?(I guess) Attached is my result of unwrapped phase and I don't know how to check the errors. Hope you can help me. Thank you so much.