3 issues couchbase 6.5

issue # 1:
installing couchbase 6.5 on windows 2012 server - it installs fine but when I try to access the web console the page is blank, no error just a blank page. The install has no issues just the page is blank.

issue #2 - I have a test cluster of 2 windows nodes and 2 linux nodes, I was able to upgrade both linux nodes to 6.5 successfully, I add one node back to the cluster and rebalance successfully but after I add the other node the rebalance constantly fails. When I failover either of the linux nodes the rebalance then works. so my cluster will not rebalance with 2 5.1 nodes and 2 6.5 nodes

issue # 3 - when adding the upgraded 6.5 node I have to unselect analytics and eventing other the addition of the node to the cluster fails

this is a test cluster for me to learn couchbase and running a cluster with different OS’s

couchbase version 5.1
windows 2012 sevver (2 nodes)
centos 7.7 (2 nodes)
4 node cluster

any suggestions/thoughts welcomed