Thank you all for your replies. As you can see in my orinial post I did clear cache, relogged several times and tried to do the character test. To have a folder with skin, shape, hair etc. to replace all I'm wearing didn't work since SL kept telling me it couldn't change until clothing and shape are loaded. And yes, my inventory was completely fetched.
I found the solution myself. Since I'm not a fan of having stuff in my inventory I NEVER use, I turned the LL library off in debug settings. This saves almost 2k in the inventory.
However, by doing so the character test doesn't work. So when I turned it back on I was able to do the char test and finaly replace my own things again.