The issue seems to be incompatible arguments to max elements.
>> B = braidlab.braid([1,-2],'vpi')
B =
< 1 -2 >
>> B.n
Error using max
Mixed inputs must be either single and double or integer and scalar double. All other combinations are not allowed.
Error in braidlab.braid/get.n (line 276)
value = double(max(max(abs(obj.word))+1,obj.privaten));
Silly me: there are no VPI braids. But this uncovered a bug in braid.setn that allowed setting non-numeric values as number of strands. Fixed by 52e1e46cafa42af53e4dec991341d0000308da33
The issue seems to be incompatible arguments to max elements.