I'm going to try to offer some solutions for you, I cannot promise they will work but I will try my best for you.
First thing, make sure key.dat is not read-only. I don't think this is a real issue since it seems Blockland makes a new one if you delete it anyway.
To find out you would right-click the file then go to properties.
Another solution is to make sure your firewall is allowing Blockland to access the internet. If you're using Windows firewall you should try upgrading to Comodo's free firewall as I always had problems with Windows firewall. If you want more support with this feel free to PM me and I will aid you the best I can.
If your IP changes this can cause you to need to reactivate the key. Although sometimes I find myself needing to reactivate a key at random times. It appeared to be when my local IP changed, though I cannot confirm this for myself.
If your IP changes you can ask your ISP for a static IP, in most cases they will give you a static IP. Some ISP's may charge for this service.
You can try making your local IP static from within the router, but again, i cannot confirm if this will help anything or not.
If your key is shared this will cause your key to switch to demo mode. In this case you can find out from Badspot if an outside source is accessing your key. You can also do an
RTB ID Lookup to find out when it was last used. Though this may only work if they use RTB.
If you have any questions feel free to PM me and I will do the best I can to help.
