A warning, in case others have the same problem I had.
In the past you could configure mhttpd so that the 'Elog' button would redirect to an external ELOG server; to do this you only needed to create and set the ODB variable '/Elog/URL' to the URL of your external ELOG server.
But with the newer MIDAS you need to set two ODB variables:
* "/Elog/URL" needs to be set to the URL of the external ELOG.
* "/Elog/External Elog" needs to be set to 'y'
I hadn't noticed this and was confused why my Elog button wasn't working after upgrading MIDAS.
MIDAS documentation was updated to reflect this change: