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Core 2.1 Modbus I/P data source error

  • Background:
    Was running Core 2.03 and Modbus I/P (both unlicensed). Had five Modbus I/P data sources setup with less than 20 registers each. Worked fine.
    Decided to upgrade to Core 2.1 and associated modules as I want to move to licensed versions.
    Had problems upgrading, so uninstalled 2.03 and installed 2.1 then setup one Modbus I/P data source with five registers. Works fine.

    Tried to add a second Modbus I/P data source, but when trying to save the Modbus IP Properties, get the following error:
    com.serotonin.m2m2.http.vo.HttpReceiverDataSourceVO cannot be cast to com.serotonin.m2m2.modbus.vo.ModbusIpDataSourceVO

    I have restarted the instance a few times.
    I removed the HTTP data source and restarted the instance, then tried again to add a second Modbus I/P ds, but now get "A server error has occured".

    Any help is appreciated.

  • Hi Glen,

    Did you clear your browsers cache? Here are the upgrade instructions in case you missed them:


  • Hi Joel,

    I switched browsers from IE to Firefox, but no help (of course MS updates installed IE11..).

    I did find the problem...
    JRE1.6 was installed, and the partially allowed Mango to function.
    I installed JRE1.7 (client version) and had no functionality at all...
    So I installed the server version of JRE1.7 and now seem to have everything I need immediately working fine.

    Thanks for your quick response.

  • That is interesting. Also make sure you have JDK 1.6 or 1.7 installed and you may need to set a JAVA_HOME environmental variable pointing to the JDK installation.


  • Joel, yes I did have to set JAVA_HOME as well.

    Quick side question - where can I change the Mango web server port from 8080 to another port ... 9999 for eample?

  • It's in the /classes/ file.


  • What was installed, and the partially allowed Mango to function.