If OpenID is used, then clients must be able to handle the token login and the RFS authentication must also be able to handle Bearer Token. Client < 12.6 were not yet able to handle this. So if it is turned on, an upgrade is absolutely required.

Sitesetupsync has been removed. Clients should be able to manage this, because the protocol has been asynchronous and if the server does not provide, then it won't be used.

Syncing of RFS is not up-to-date in any case in older versions, because the checkchanges call has been added for starting.

The handling of the psolrights.cfg slightly differs for ERP users in the old versions: (there, the user=roleset workaround still exists, which has been removed in V12.6).

Only versions >= 12.6 can deal with ERP users with groups (the older ones will simply ignore that).

The DB connection configuration differs from 12.6. So problems could occur if the clients do not understand this new variant and evaluate configs according to the old manner. May be that this is not relevant due to remote-db, however, without it problems will arise, because the dbproxy.cfg is missing and furthermore the database proxy setting does not exist anymore in the plinkcommon.cfg. Also database users are expected where they do not exist necessarily in the meantime...See Section 4.7.2, “ Database connection ”.