I am trying to create two blocks and save them. I could not create a block and restarted my computer. This allowed me to actually create a block and save it, which I did to the desktop. I opened a different sketch and created a block and clicked the green check mark but it would not turn the selected lines into a block. reloaded my saved setting and it allowed me to make a block and save it. I tried, just out of curiosity, to make the same block and was not able to.