Question: Error, `DifferentialAlgebra` does not evaluate to a module

> with(DifferentialAlgebra:-Tools);
Error, `DifferentialAlgebra` does not evaluate to a module
with(DifferentialAlgebra):
> with(DifferentialAlgebra);
Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package}, but received DifferentialAlgebra

don't know why maple 12 give these error, how to import differentialalgebra package?

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