While trying to answer this question I encountered an internal error using a Part specification to extract data for specific columns from a dataset.

dsMeetings2 = 
 Dataset@{<|"id" -> 1, "date" -> "1/03/20", "name" -> "subject-1", 
    "100" -> 1, "106" -> 1, "101" -> 1, "105" -> 1, "102" -> 1, 
    "104" -> 0, "108" -> 0, "103" -> 0, "109" -> 0, "111" -> 0|>, <|
    "id" -> 2, "date" -> "8/03/20", "name" -> "subject-2", "100" -> 1,
     "106" -> 1, "101" -> 1, "105" -> 1, "102" -> 0, "104" -> 0, 
    "108" -> 0, "103" -> 1, "109" -> 0, "111" -> 0|>, <|"id" -> 3, 
    "date" -> "15/03/20", "name" -> "subject-3", "100" -> 1, 
    "106" -> 1, "101" -> 0, "105" -> 1, "102" -> 1, "104" -> 1, 
    "108" -> 0, "103" -> 0, "109" -> 0, "111" -> 0|>, <|"id" -> 4, 
    "date" -> "22/03/20", "name" -> "subject-4", "100" -> 1, 
    "106" -> 0, "101" -> 0, "105" -> 0, "102" -> 0, "104" -> 0, 
    "108" -> 1, "103" -> 1, "109" -> 1, "111" -> 0|>, <|"id" -> 5, 
    "date" -> "29/03/20", "name" -> "subject-5", "100" -> 1, 
    "106" -> 0, "101" -> 1, "105" -> 1, "102" -> 1, "104" -> 1, 
    "108" -> 0, "103" -> 0, "109" -> 1, "111" -> 0|>, <|"id" -> 6, 
    "date" -> "5/04/20", "name" -> "subject-6", "100" -> 1, 
    "106" -> 0, "101" -> 0, "105" -> 1, "102" -> 0, "104" -> 0, 
    "108" -> 0, "103" -> 1, "109" -> 1, "111" -> 1|>}

dsMeetings2[All, {1, 3 ;;}]

General::interr2: An unknown internal error occurred. Consult
Internal`$ LastInternalFailure for potential information.

I can post the long results from Internal`$ LastInternalFailure if that would help.

This unexpectedly works fine

dsMeetings2[All, {1, 3 ;;}] // Normal

so does this

dsMeetings2[All, {1, 4 ;;}]

Any ideas for workarounds without converting to Normal?

I will report this to WRI.