We are having currently Confluence 3.5.13 in the production. Now in the recent future we are planned for an upgrade to Confluence 4.2.5. While migrating the production data to SI as part of the version upgrdation, we are facing an error while trying to copy the wiki markup. While trying to save the Wiki markup we are experiencing an error. PFA the error image.

my guess now is that the number-dataoption is not properly used in Conlfuence 3.5.13.
Could anyone please help me out in this matter?