Answer:
The description of various load combinations must not be the same, otherwise the error message shown in Image 01 will be displayed. The relevant load combination can be taken from the error message (Load Combination No. 2 in Image 01).
The model shown in Image 02 contains the load combinations LC1 and LC2. Both load combinations have the same description "ULS". It is necessary to change one of the two descriptions so that the import is possible.