Can't open issue after comment manipulation

[Ludvig Sjöbom]

One of my agents changed the visibility of one comment from external to internal, and another added an internal comment in that issue. Afterwards, we are no longer able to open that issue. I can find it when searching for it by key or all issues in that project. When I click it I get an error message to the effect of "[Key] cannot be opened. It might be removed or you do not have the permission to view it.". On opening the next issue in the list and selecting the arrow for next issue, I get "Issue cannot be shown right now, this might be a network- or application problem. Try reloading". On reload, I get 502 - Web server received an invalid response while acting as a gateway or proxy server.

My agent is in the appropriate group for the project, and can work on other issues just fine. I am in the jira-administrators group, and can also view other issues in the project.

What I tried so far:

https://community.atlassian.com/t5/Jira-questions/This-issue-can-t-be-viewed-The-issue-you-re-trying-to-view-can-t/qaq-p/337889

But the issue security scheme seems to be OK, and atlassian-jira.log does not show anything obvious regarding status properties.

https://confluence.atlassian.com/jirakb/opening-of-jira-issue-navigator-fails-with-exception-500-314450157.html

But the SQL to verify the problem gives a clean result.

https://confluence.atlassian.com/jirakb/issue-can-not-be-opened-error-when-trying-to-select-it-in-the-issue-navigator-376832648.html

Null value in the created column of the fileattachment table? No, attached SQL gives nothing.

Finding the issue via the jiraissue table in the database shows it as being similar to other, working, issues. In the jiraaction table no comment for this issue stands out as different.

Cloning the issue gives me a 502 error, but the service desk team for the project got an email about a new issue being created by me. The new issue shows the same symptoms as the original.

The log scan shows https://confluence.atlassian.com/display/JIRAKB/Unable+to+create+new+issues+after+upgrading+to+Jira+7?utm_source=STP&utm_medium=logScan But we are able to create new issues without problem and server.xml is set properly.

Log scan also shows Connection reset while accessing database, but the date does not match.

Jira service desk 4.5.0-REL-0034

Jira 8.5.1