Background:


I had an issue with Ageas Retail where every time they were registering users on only 2 servers - that they were getting failed to register user error.

We tried everything and worked fine if we moved them to another server.


Cause:


The issue was a database replication issue.


Because they operated a multi-server cluster. This means that they had 4 slave servers and a master.

When we looked in SQL studio manager at the publications; where server replications from SafeCom are kept there was only 2 servers, not the other 2 having the issue.


We feel it must have been removed manually by mistake.

But SQL team advised they have never removed any.


Resolution:


I had to give the SafeCom account sysadmin rights again; it does not require these rights to run normally but if you need to repair replication you will need this rights.

Once these rights were given.


I then went onto SafeCom administrator, right-clicked each server and repaired replication.

Once it repaired successfully - they all appeared in publications within SQL.


FYI, you cannot repair replication of master as this is where they are all pointing; ignore master one.


Tested and now users on all servers can register fine.