Content Library not loading.

I am having the same issue. When using Rise (online) I get several rows of thumbnails and then a few rows of warning triangles. If I click on a warning triangle the 'mystery' image imports. I can replicate the issue in the locally installed Storyline 360 except clicking on a warning triangle leads to a 'download failed' error. I ran diagnostics through the Articulate 360 Web App and found a clue under the LOGS > LATEST MESSAGES:  

[10:19:40] Download failed: https://pixabay.com/get/54e8dd474a50af14ea89877ecf29327c1322dfe05455734f752b7bd5.jpg; The remote server returned an error: (503) Server Unavailable.

There are dozens of entries for what appears to be several images over the course of just a few seconds. Our IT support desk has asked that connect with customer support. I stumbled upon this thread and figured I would update with my details first.