DRAFT KB-XXXX Process model swim lanes disappear and connectors become diagonal

Symptoms

A process model that used to have swim lanes and standard vertical/horizontal connectors now has no swim lanes and diagonal connectors. This change is depicted in the screenshots below:

In addition, the application server log prints one of the following three error messages:

1. "Access is denied" error:
   
   

   ERROR com.appiancorp.process.design.service.ProcessDesignServiceXmlImpl - An error occurred retrieving the model from the filesystem.
   java.io.FileNotFoundException: <APPIAN_HOME>\_admin\models\<XXX>\<PMUUID>\draft.xml (Access is denied)

   
   
   
2. "The system cannot find the path specified" error:
   
   

   ERROR com.appiancorp.process.design.service.ProcessDesignServiceXmlImpl - An error occurred retrieving the model from the filesystem.
   java.io.FileNotFoundException: <APPIAN_HOME>\_admin\models\<XXX>\<PMUUID>\draft.xml (The system cannot find the path specified)

   
   
   
3. Mismatch:
   
   

   Insert error code here.

Note: if you are using Appian 7.11 or earlier and experience the issue depicted in the above screenshots, please reference KB-1001.

Cause

1. The process model's most recent XML file, draft.xml, is not accessible in the filesystem (it is locked, the shared folder is unavailable, or the application server does not have the correct permissions to access it).
2. The process model's most recent XML file, draft.xml, has been deleted from the filesystem.
3. There is a mismatch between the process design and the filesystem. This can happen when the environment engine database KDB file for design (pd*.kdb, located at <APPIAN_HOME>\server\process\design\gw1) has been reverted to a previous date. In this case, the older KDB file will not include the most recent transactions performed on the process model. This will cause a mismatch between the contents of the pd*.kdb file and the draft.xml file.

Action

1. Ensure that the draft.xml file is unlocked and that the appropriate folders in the <APPIAN_HOME>\_admin\models shared directory are accessible. In addition, ensure that the user that is running Appian has appropriate permissions on the draft.xml file. To prevent this issue in the future, do not virus-scan or back-up the models folders during business hours.
2. Restore the XML file from a back-up. To prevent this issue in the future, do not delete XML for models directly from the filesystem.
3. Copy the most recent checkpointed pd*.kdb file from <APPIAN_HOME>\services\data\archived\process-design to <APPIAN_HOME>\server\process\design\gw1 and rename it so that it is numbered higher than any of the KDB files in the <APPIAN_HOME>\services\data\archived\process-design directory. Delete the other KDB file in <APPIAN_HOME>\server\process\design\gw1 so that the file that was just copied over (and renamed) is the only existing file in the directory. To prevent this issue in the future, do not revert to a previous pd*.kdb file without the help of Appian Support.

Affected Versions

This article applies to Appian 16.1 and later.

Last Reviewed: May 2018