Citing Taher's message at :
I received emails and checked resources  that seem to confirm JCenter from JFrog is going down and that the last day of operation for the repository is going to be May 1st 2021.
This is a big deal as many running instances will crash unless updated, so not only do future versions of OFBiz need to adapt, but also existing installations.
I'm not sure how to best handle this? Especially for production instances out there on older versions of OFBiz. Maybe one solution is to host the existing libraries in some temporary location or try to migrate them to MavenCentral ... Whatever is the solution I think we should make a fast move.