Thanks for bringing this to our attention. Have few questions to narrow down the problem:
What is the size of the file/directory you are trying to add?
What command are you running when adding?
How far does the add operation make it before stalling?
Are you able to run other commands when the add it hanging? Try running
ipfs id, does that work?
You may also find the comments in this issue helpful, specifically:
For now, when adding very large sets of data, its advisable to do so without the daemon running, or by using
ipfs add --local. The issue is that you will clog up the DHT when adding such huge volumes of objects, and that slows everything else your node is doing down. It then also has the impact of consuming lots of extra memory.
Edit: Issue I forgot to link - https://github.com/ipfs/go-ipfs/issues/3885