It looks like you have shadowed the builtin function strsplit by a user-defined function, which accepts less inputs.
If you post the complete error message, it would be easier to check, if this assumption is true.
Check this by:
What do you get as answer?
To avoid such troubles, do not append folders on the top of the Matlab path, but on the bottom only. Then the user defined strsplit() is shadowed, which can cause bugs also, but it is easier to find them. The solution is to rename the user-defined function.