Just migrated my second server form 7.5 to 7.9 and encountered this issue as Jbo

...9:16,367 [ServerService Thread Pool -- 59]
INFO com.appiancorp.type.config.plugin.PojoDatatypesConfig - adusersynchronizationwithusernames:LdapResponse: The provi
ded XSD file contains a definition for the type {urn:appian:plugin:directory}LdapResponse, which already exists with the
same structure. (APNX-2-4045-004)
13:10:02,195 INFO [stdout] (ServerService Thread Pool -- 59) 2015-07-09 13:10:02,194 [ServerService Thread Pool -- 59]
INFO com.appiancorp.type.config.plugin.PojoDatatypesConfig - com.appiancorp.ps.logreader:LogFile: The provided XSD file
contains a definition for the type {com.appiancorp.logreader}LogFile, which already exists with the same structure. (AP
NX-2-4045-004)
13:10:02,394 INFO [stdout] (ServerService Thread Pool -- 59) 2015-07-09 13:10:02,394 [ServerService Thread Pool -- 59]
INFO com.appiancorp.type.config.plugin.PojoDatatypesConfig - com.appiancorp.ps.logreader:LogContents: The provided XSD
file contains a definition for the type {co...

...m.appiancorp.logreader}LogContents, which already exists with the same struct
ure. (APNX-2-4045-004)
13:10:02,629 INFO [stdout] (ServerService Thread Pool -- 59) 2015-07-09 13:10:02,629 [ServerService Thread Pool -- 59]
INFO com.appiancorp.type.config.plugin.PojoDatatypesConfig - com.appiancorp.ps.logreader:CsvContents: The provided XSD
file contains a definition for the type {com.appiancorp.logreader}CsvContents, which already exists with the same struct
ure. (APNX-2-4045-004)
13:10:03,035 INFO [stdout] (ServerService Thread Pool -- 59) 2015-07-09 13:10:03,034 [ServerService Thread Pool -- 59]
INFO com.appiancorp.type.config.plugin.PojoDatatypesConfig - com.appiancorp.ps.logreader:CsvReport: The provided XSD fi
le contains a definition for the type {com.appiancorp.logreader}CsvReport, which already exists with the same structure.
(APNX-2-4045-004)
13:10:14,800 INFO [stdout] (ServerService Thread Pool -- 59) 2015-07-09 13:10:14,799 [ServerService Thread Pool -...

... - 59]
WARN com.appiancorp.type.config.plugin.PojoDatatypesConfig - psshared.peoplefunctions:userSecurityRoleMap: The provided
XSD file contains a definition for the type {urn:appian:ps:peoplefunctions}SecurityRoleMap, which already exists with a
different structure. The requested type will not be created and the existing type will not be altered. You must first d
elete the existing type if you intend to redefine it with a different structure. (APNX-2-4045-001)

Immediately after this the plugins register and the server boot up completes.
What has caused this issue and how do I eliminate it? Clearly the problem appears to be related to some custom plugins which are available in the plugin directory.

Thanks, James

Does Appian function correctly after booting up?

It looks like you migrated over data from the previous version, and with that you brought CDTs that are used in some custom plugins. When these plugins boot they try to create the necessary CDTs, but since you already have them in the environment new ones are not created. I don't think this will cause any issues.

This is a false positive. If you deploy a CDT as a POJO and this CDT contains a nested multiple as one of its fields, every time you restart the application server you will get a message stating that the CDT already exists with a different structure even if nothing changed and it's just a restart of the application server.

This can be safely ignored. The reference number to remove this red herring in a future version is AN-49344.

-Eduardo
Cloud and Community Services

Thanks conorc and Eduardo.
Appian is indeed functioning correctly.