Source of the error message is not displayed in the WYSIWYG editor when executing a script without scripting rights

STEPS TO REPRODUCE

1. Login as Admin
2. Create an user (U1)
3. Go to Administer Wiki > Users & Rights > Rights
4. Deny the Script right for U1
5. Create a page (e.g. Pag1)
6. Insert a Velocity Macro (or other macro requiring script rights) and save the page
7. Login with U1
8. Edit the page containing the macro
9. Check the result in the WYSIWYG editor

EXPECTED RESULTS

Due to the fact that U1 has no script rights, there is an error message that also contains the source of this error:

Failed to execute the [velocity] macro. Cause: [The execution of the [velocity] script macro is not allowed in [xwiki:Main.Pag1.WebHome]. Check the rights of its last author or the parameters if it's rendered from another script.]. Click on this message for details.

ACTUAL RESULTS

The error message does not display the source:

Failed to execute the [velocity] macro. Cause: [The execution of the [velocity] script macro is not allowed. Check the rights of its last author or the parameters if it's rendered from another script.]. Click on this message for details.