The user gets a user notification that says, "The SWMM engine failed during the calculation" when using a hot start file with the SWMM solver.
1) Delete the storms from the Storm Data manager if computing a dry weather scenario.
2) Set the “Apply SWMM RTK Unit Hydrograph Set” property to "false" for all the manholes using the flextable. This can be done using the global edit feature.
3) Create a new hot start file and run the scenario again using it.