I have an Atlassian support request open for this, but I'm hoping someone else has seen this and can help.
After upgrading from 8.20 to 9.4.6, I see that issue history is not being shown. In place of where it should be, I see the following lines repeated for each history slot:
Anonymous made changes - Invalid date
When I check the logs after reloading the issue, these lines appear:
2023-05-31 16:55:41,778-0400 https-jsse-nio-127.0.0.1-8443-exec-18 WARN mschultz 1015x1392x1 1hx4fwa 127.0.0.1,127.0.0.1 /rest/wrm/2.0/resources [c.a.j.plugin.editor.RteDataProvider] "jira.rich.editor.content" context supports only CSS resources, please review atlassian-plugin.xml, some <resource> or <dependency> is including different resource type.
NOTE: This is happening in Safe Mode as well.
