Cannot play Offline songs on Laptop

[Ambugaton]

Plan

Premium

Country

Sweden

Device

(Intel Core, i5-3320M CPU 2,6 Ghz, 4 Gb RAM, Lenovo)

Operating System

(Windows 7, 64-bit system)

My Question or Issue

My Lenovo laptop cannot play offline songs. I have re-installed and re-downloaded all the songs (less than 2000) over 3 times now, I have synced these downloaded files, put my laptop on Offline Mode, and still the message says (originally in Swedish) "Spotify can't play this right now. If you have the file on your computer you can import it" BUT I've all ready done this several times, and since these song files are downloaded to C:\\user\USERNAME\Appdata\Local\Spotify\Storage then this folder builds up over time and use up tons of memory on the laptop, if I don't delete the whole Storage folder again and again after each re-install.

I have been a Premium user for some years now, and I have all ready checked several threads on this community and nothing solves this - I keep coming back to re-installing. Please help and only RELEVANT answers, no Off topic on mobile phones, THANKS.

EDIT: I've also unchecked Hardware acceleration, log-out all devices (only 2 of them), deleted the local-files.bnk/renamed it. Still no solution.