Technical Term for Incorrect Homonym/Synomym Error

Solution 1:

Regarding the blunders we often find in machine translation, let me offer polysemy error.

polysemy: multiplicity of meaning

(Webster's Unabridged)

When a computer encounters a polysemant, it often fails to choose the correct meaning in context, which results in a polysemy error that we often find humorous.

By the same token, you could use homonymy errors, when the mixed-up words are homonyms or homographs.