A few weeks ago, I purchased the electronic edition of the 3rd volume of the GIA choral hymnal. Among the features in the software that accompanied the hymnal that I purchased, is a feature that allows users to import music from their Dropbox accounts. I was delighted. I used the feature, and it worked without incident. The second time, I was not so successful; I received this error message: "API auth error - {".tag" = "expired_access_token";}." Can you help me fix the problem? The GIA website doesn’t have a support link. Dropbox support suggest I post here.