A macro for Foundry VTT `0.7.10` or below to fix any corrupted quest data w/ and old version of Forien's Quest Log.

gistfile1.txt

(async () =>
{
   const folder = game.journal.directory.folders.find((f) => f.name === '_fql_quests');

   // Stop now if no FQL quests folder exists.
   if (!folder) { return; }

   for (const entry of folder.content)
   {
      // Detect and skip any new style FQL quests.
      const json = entry.getFlag('forien-quest-log', 'json');
      if (json !== void 0) { continue; }

      // Strip leading / trailing HTML tags in case someone attempted to look at / modify the JE.
      let entryContent = entry.data.content;

      try
      {
         JSON.parse(entryContent);
      }
      catch (err)
      {
         console.log(`Forien Quest Log | detected corrupted quest data for: '${entry.data.name}' attempting to fix.`);

         entryContent = entryContent.replace(/^<p>/, '');
         entryContent = entryContent.replace(/<\/p>$/, '');

         // These regex substitutions will attempt to reverse damage to the stored JSON.
         entryContent = entryContent.replace(/("\\&quot;|\\&quot;")/gm, '\\"');
         entryContent = entryContent.replace(/:">/gm, '\\">');
         entryContent = entryContent.replace(/:" /gm, '\\" ');

         // Non-printable characters need to be removed; replace the entire range of non-printable characters.
         entryContent = entryContent.replace(/[\x00-\x1F]/gm, '');  // eslint-disable-line no-control-regex

         await entry.update({
            content: entryContent,
         });
      }
   }
})();