Hi, noted. If you have the databases as backup on an external drive, this is good, you can simply move the files to your computer and restore them. It sounds a bit like a hardware issue though (disc corrupt or totally full, etc., so check this). Or, you have specified a different database folder in the openLCA ini file. Or, the json file which summarises the databases to be seen has been moved or deleted. Are the databases physically still in the database folder?
