And they weren't just in Spain; there were large Jewish communities in the Holy Roman Empire throughout most of the period you're claiming they weren't a thing in Europe — in fact, Yiddish is famously a fusion of Hebrew and High German — and Louis XIV issued letters of patent to the Jewish community in Alsace in the 1600s. Many of the Jews expelled from Spain were initially welcomed by the Papal States, who already had existing Jewish populations — until they were expelled from the Papal States by Pius V in the 16th century. Venice oppressed their Jewish population brutally and confined them to ghettoes, but of course, they existed — otherwise there would be no ghettoes. Not to mention the massive Jewish presence in the Grand Duchy of Lithuania, which was one of the largest European states in the 1500s, although given your backtracking to "Western Europe" perhaps you don't consider the Grand Duchy to be "civilizational European." And in the 1600s, Denmark began explicitly encouraging Jewish immigration from the rest of Europe, due to the Danish fiscal crisis from the Thirty Years War, with hundreds of thousands of Jews moving.

You are simply wrong.

Honestly, given the level of Israel/Palestine conspiracy takes on Jews never having existed in the Middle East, or having no presence there until the 20th century (also wrong), I'm somehow shocked to find someone with a theory that Jews didn't exist in Europe prior to the 19th century.