It's basically the title, and idk why it is crashing while launching the server. It's happening to both the non-Steam version and the Steam version of BL.
conflicting add-on / something is wrong with your blockland, try running a server without your add-ons, then if that doesn't work rename add-ons folder to add-ons1 and it'll redownload add-ons, if that doesn't work, try a reinstall.
If it works without add-ons then try and find the add-on conflicting by process of elimination.
