Last Friday (10/3) my Cloud API upload calls started failing (code 100). Today I spoke with GroupDocs support (Ihor) today and found that the API signature has changed. Ihor said that they are working on a fix that may not require client-side changes. However, if changes are required, they may release a new version of their SDK (in this case, the PHP variety).
If a code change is required, could GroupDocs please reply to this thread? If a code change is not required, could we get an update when the issue is resolved? Thank you!