Issues faced when migrating from version 1.13.2 to 1.14.0 and 1.15.0-SNAPSHOT

[Anisha Jaiswal]

Hi,

I am Anisha Jaiswal and am using Apache Isis to build an application.
I am facing a couple of issues...could you please help me out here:

1) I am currently using the core version 1.13.2 and decided to upgrade to
1.14.0 since it supports collection parameters in action methods.
I use maven to build my application. After running the build for version
1.14.0, i got the error:
*Missing isis-core-viewer-wicket-impl-1.13.1.jar*. It wasn't able to
download the jar.

Here is how i had given the dependency in my pom:

            <dependency>
                <groupId>org.apache.isis.core</groupId>
                <artifactId>isis</artifactId>
                <version>${isis.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

where isis.version is 1.14.0

Is there any other dependency i need to include ?

2) Then i decided to try version'1.15.0-SNAPSHOT', which is still under
development.
The application got built properly for this version. It was able to
download the isis-core-viewer-wicket-impl jar for this version.

But the issue that i am facing now is that as soon as i try to show a
collection in my ViewModel it gives me the *IsisAssertException: POJO Map
already contains object*
These collections were working fine in version 1.13.2.
This is how i have the collection specified in the layout.xml of my
ViewModel:

    <collection id="students" defaultView="table" />

And the corresponding method in the java class is:

public List<Student> getStudents() {
List<Student> responseList = new ArrayList<>();
.
.
return responseList;
}

*When do we get this exception and how do we resolve it ?*

*Any help on these issues would really help my project.*

Thanks a lot,
Anisha