Is this a valid Takuzu board?
Brachylog, 20 18 bytes
≠\≠,?¬{∋s₃=|∋ọtᵐ≠}

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Explanation
≠                           All rows are different
 \                          Transpose
  ≠                         All columns are different
   ,?                       Append the list of rows to the list of columns
     ¬{          }          It is impossible that:
       ∋                      A row/column of the matrix…
        s₃=                   …contains a substring of 3 equal elements
           |                Or that:
            ∋ọ                The occurences of 1s and 0s in a row/column…
              tᵐ≠             …are not equal