Known Issues

Known Issues of the SemSpect Neo4j Graph App #

This page contains information about all known issues of the latest release of the SemSpect Graph App.

Settings get lost on DBMS upgrade with Neo4j Desktop #

During an upgrade of a DBMS, Neo4j Desktop will not copy the SemSpect contents from the plugins folder of the DBMS to the new location before deleting the old installation. The SemSpect plugin can be reinstalled but the user settings (saved explorations and user defined SemSpect label) will be lost.

To prevent this, make a copy the semspect_data folder from the plugins folder of the DBMS before starting the upgrade and move it to the new plugins folder after the upgrade.

Open the plugins folder and copy semspect_data

Missing Credentials with Remote DBMSs #

When SemSpect is used with a remote DBMS, it may complain about missing credentials:
Missing credentials
In this case make sure that your Neo4j Desktop is set up to store passwords:
Settings Store passwords

NO_VALUE Error during Filter Operation #

Due to an issue in databases version 4.0.0 to 4.0.8 and 4.1.0 to 4.1.3 , the filter operations in the details of a group might fail if there is no value given for some attributes of some objects, although the same data in a database version 3.5, 4.0.9 or 4.1.4 work as expected.

Filtering with empty values 1
Filtering with empty values 2

Workarounds:

  • Recommended: update your database to version 4.0.9+ or 4.1.4+
  • If not possible:
    • use specific filters on the columns without missing vaue
    • if a multi-column filter is required, hide the columns that have missing values
    • if you have to filter on a column with missing values, give the objects an empty/dummy value if that is acceptable for your model
      Filtering with empty values 3

Data out of sync with first custom category creation after upgrade to DBMS version 4.3 #

Due to a modification in the transaction handling with Neo4j version 4.3, the first creation of a custom category after upgrade from another version will respond as if the graph data was out of sync. In this case refresh SemSpect as requested, it will happen only once.

Context Menus not working #

Due to an issue with the older Electron browser used by Neo4j Desktop prior version 1.4.6, some UI interactions do not work after loading or reloading SemSpect (context menus, etc.).

Workarounds:

  • Recommended: update Neo4j Desktop to a version ≥ 1.4.6.
  • If not possible, each time SemSpect is loaded click anywhere outside of the SemSpect window and then in the SemSpect window again.

Server Error when applying restrictions with labels from details tab #

Some combinations of restrictions that use labels from the details tab result in a Neo4j query planning problem indicated by the following server error:

org.neo4j.graphdb.QueryExecutionException: Expected RegularSinglePlannerQuery

Neo4j fixed this in version 4.4.6 (see Neo4j issue #12862).

Workaround:

  • Recommended: update your DBMS to version ≥ 4.4.6.

“Unexpected Error” on start #

Until now this error has only occurred with Windows computers maintained by corporate IT services. In all cases so far, this problem could be solved with the following workaround.

Workaround:

  • remove JAVA_TOOL_OPTIONS from Windows system environment
  • restart Windows