Unfortunately, the ARXML export doesn’t work with the EAPX format. To use the export functionality with, please transfer the data to a project file with the EAP format.
To convert or exchange the data, there are multiple ways.
1.) Copy / Paste Package
In the eapx file, right-click the package in the project browser and select "Copy / Paste > Copy to Clipboard > Full Structure for Duplication"
Then head to the eap file, right-click any package in the project browser and select "Copy / Paste > Paste Package from Clipboard"
2.) XMI Export / Import
In the eaxp file select the package (or the model root package "Model" of the whole file) and go to the ribbon group "Publish", the category "Model Exchange" and select "Export-XML > Export XML for current Package". Select a location for the export and start the XMI export.
In the eap file select a package where you want to import the package and go to the ribbon group "Publish", the category "Model Exchange" and select "Import-XML > Import Package from XMI". Select the XML file from the previos step and start the import.
3.) Project transfer
In contrast to step 1) and 2), this method copies and converts the entire EA project from EAP to EAPX.
At first, create a new EA project of type EAP. Make sure to close the newly created project.
Next, open the EAPX file that you want to transfer. Go to the ribbon group "Configure", the category "Model" and select "Transfer > Project Transfer". For the "Transfer Type" select "File to File" and configure the two files (Source Project = the EAPX file, Target Project = the newly created EAP file). To finish the transfer hit the "Transfer" button.
If there are any errors during the transfer, make sure the Target Project is not blocked by any process.