Reproduce:

• Try to open an embedded form when the context path is missing (e.g. due to a misconfiguration of the server)

Expected:

• the tasklist does not try to load a file from the nonexisting protocol app:embedded
• an error message "missing context path" is shown

Observed:

• the tasklist does try to load a file from the nonexisting protocol app:embedded
• error message "cross origin not allowed" is shown