If you have so many store items installed in your game, this might be happen.
First, don't open your launcher yet.
All I can tell you is look at your DCCache folder, you can find that in My Document/Electronic Arts/
You will see something like this:
There are dcbb0.dbc and so many things right? That was your store items (and custom contents).
I can't explain why but our launcher cannot load all of our store content so...
Just look at the last .dbc. In my case it's dcdb11.dbc
Just rename the first dcdb01.dbc to something else like dcdb0x.dbc let it stay that way it wouldn't be harm.
Then rename dcdb11.dbc to dcdb01.dbc. You get it?
Good.
Now open your launcher and your last installed content should be there and you can uninstall now.
The last thing, just quit the launcher and rename those files again to their default name.
Done!
I hope this will help!