Back-Up error

Hi, I've been using Tabs Outliner for quite a while now & it’s been working great. But for the past week, I've been getting an error that it can’t back up my tabs. I thought I'd reinstall it, which just made things many times worse. I lost my entire tab structure & I had paid for it a long time ago which always transferred over but it didn’t after I reinstalled it. I thought I would pay again but it’s not even acknowledging my purchase. Now I can't even edit what I have there to even recreate it. Please help!