May have figured this out. I did upgrade to the new version pro 3.3.0.
New version was sort of working with the Browser upload, but Flash Upload was not working. I had Sucuri Security installed (use this on all my sites), and had been using the hardening settings for the Uploads and Content folders, which installs htaccess files. I uninstalled Sucuri, and deleted both htaccess in Uploads and Content folders. Files have been uploading with no issues so far.
Upon reinstalling Sucuri, and hardening those 2 folders, I do get the errors again. So check htaccess in those folders and check any security plugins