al6xis You can restore the Sims 4 folder that was in Documents > Electronic Arts, as in, move it back or rename it to "The Sims 4," to get your saves back.
I really don't understand why this is happening, since you've done all the usual steps so far. To be sure, you've loaded a new save and tried to create a pet, and looked for Brindleton Bay in the list of worlds? And if you use mods, you've tested with out them?
Other than that, let's make sure that Windows search isn't missing something, please download Everything, from VoidTools, which is a free and highly-efficient search tool. Use it to search for EP04 and post the results; here again, please include all the results and make sure the entire path to each one is visible.