|||{{headline}}D.C. residents had serious trouble registering for coronavirus vaccination appointments online Thursday.D.C. residents had serious trouble registering for coronavirus Thursday.More than 4,000 slots were supposed to open at 9 a.m. for anyone 18 and older with qualifying medical conditions but many residents ran into roadblocks when they tried to register.Others said they weren’t being allowed to register because they are under 65, even though they have preexisting conditions.D.C. Mayor Muriel Bowser blamed the volume of traffic to the website.Due to the high volume of traffic...…|||{{headline}}D.C. residents had serious trouble registering for coronavirus vaccination appointments online Thursday.D.C. residents had serious trouble registering for coronavirus Thursday.More than 4,000 slots were supposed to open at 9 a.m. for anyone 18 and older with qualifying medical conditions but many residents ran into roadblocks when they tried to register.Others said they weren’t being allowed to register because they are under 65, even though they have preexisting conditions.D.C. Mayor Muriel Bowser blamed the volume of traffic to the website.Due to the high volume of traffic...WW…