Question about Upgrade from UCS-4 to UCS5

letsencrypt is present in the app center, but I can not reach install page. every time I try to install it, its ends in a non-responsive page. (app center page with central gif rolling, with no response, I can’t even not reach install page). Others packages install successfully, or at least I can reach the install page. I have made 2 distinct install of ucs-5 and see the same problem with letsencrypt.