I’ve ran across this problem recently and have seen that it happens to quite a few people using chrome.
You are using Gmail, or another online site and click on a button to add an attachment or upload a file and all of a sudden chrome freezes and you see the coloured spinning wheel of death as people refer to it as.
You then need to Force Quit chrome to continue working.
To fix this, you need to delete two files:
com.apple.finder.plist and com.apple.sidebarlists.plist
Seems simple, but they are in the Library Folder which is hidden is OSX. However, to access it all you need to do is Open Finder, Click on the Go Menu then press Alt on your keyboard. Magically, you should see an option for Library appear that you can click on.
Once you have clicked on Library the files we need to delete are stored in the Preferences folder. So open it up, find the files and drag them to Trash, or if you want to keep the files rename them so you can revert if necessary.
The next step is to log out/restart your computer and log back in. This is because upon logging in OSX will recreate the two files we have deleted.
At this point – check if you can add attachments normally as this should have fixed the issue.