A lot of people are reporting this issue and claiming it goes away for good after waiting long enough. This is extremely peculiar.
If you are currently having this issue, PLEASE do the following so I can see why this is happening; we could discover something very interesting.
1) Enable trace on your blockland shortcut
1a) If you using steam: Right click the Blockland entry in your library and select Properties. Click "Set Launch Options...". Type
-trace into the box and hit OK.
1b) If not using steam: Right click your Blockland shortcut on your desktop or in the Start Menu and select Properties. Click on the "Target" field and scroll the cursor all the way to the end of it. Add a space to the end and type
-trace and then hit OK.
2) Start the game, wait until the lag starts and then force-close the game.
3) Upload your console log somewhere that allows larger files (like Dropbox, Google Drive, MediaFire,
leopard hosting)
4) Post a link to the file here so I can read it and figure out why this freeze is occurring.