Trying the slug generation task was a good idea - sometimes if a CSV import goes wrong, it can leave incomplete rows in the database, including rows that are missing slugs. However, if your description has a slug you can see in the browser, then this isn't the issue. I'll offer a few suggestions on other things to check or try below.
First, let's try a few other common troubleshooting tasks that can sometimes clear up these types of issues.
It's possible that the nested set needs to be rebuilt - this is a method we use in AtoM to manage hierarchical relationships in the flat, table-like structure of a relational database. It is also typically captured in AtoM's database using LFT and RGT columns, so it sounds quite possible that the error you've reported relates to this. If an import times out, sometimes the nested set becomes corrupted, and this can lead to strange loops in the UI, or the appearance of doubles. You can rebuild the nested set with the following:
I would also suggest that we clear any caches used in AtoM, and try repopulating the search index. First, let's clear the application cache:
I also recommend restarting PHP-FPM and, if you're using it, Memcached. The command for restarting PHP-FPM will depend on the O/S and PHP version you have installed - for AtoM 2.6 with PHP 7.2 on Ubuntu, the command is typically:
If you're using Memcached (if you're not sure, you can always try the command - it won't break anything if you don't have it installed), restart that as well:
Now, let's try to repopulate the search index, and see if that makes the description accessible:
Remember as well to clear your browser cache before retesting, or else test in a private or incognito browser tab where the cache is typically disabled by default, to ensure that you are seeing up-to-date results!
If that still doesn't work:
Any time you get a 500 error, it's helpful to take a look at the webserver logs to learn more about the exact nature of the error. We have information on how to access the Nginx error logs here:
Feel free to share any relevant error message you find, as this will help our team come up with further suggestions.
You could also try checking for some of the common forms of data corruption that may have resulted from the aborted import attempt. See this section of our Troubleshooting documentation for more information:
Start with these suggestions and let us know how it goes!