I tested this today on 14.10.18 and 15.8, with the following scenario:

• installed ludovicdubost:todo-macro version 1.0 on main wiki and subwiki
• uninstalled from mainwiki,
  • answered the question about the pages to delete at the end of the installation
• exported the xml of this uninstall from main wiki
• from the main wiki extension history section, I replayed the xml on the subwiki
• the job ended fine, no questions asked.

• then, I manually edited the exported history xml from 3rd bullet above, to remove all the content of the <answers> tag - only an <m /> empty element
• I reinstalled the extension on the subwiki
• I replayed the job on the subwiki from the main wiki
• this time, the replay job properly asked the question about deleting unused pages at the end
• answered the question and then the job continued and finished.

Based on these tests and the similarity with XWIKI-21120, I will assume that the source problem was the same one and it got fixed, I'm closing this ticket.

• then, I installed again t