Delete Issue Link causes Error rendering 'com.atlassian.jira.jira-view-issue-plugin:linkingmodule' and some Dashboard gadgets

Delete Issue Link causes Error rendering 'com.atlassian.jira.jira-view-issue-plugin:linkingmodule' and some Dashboard gadgets

Summary

Under a specific scenario, when deleting Issue Link Type, JIRA ends up with an inconsistent linktype saved in the issuelink table showing the following errors.

• When opening issues:

  Error rendering 'com.atlassian.jira.jira-view-issue-plugin:linkingmodule'. Please contact your JIRA administrators.
  

• In some Dashboard gadgets

  An error occurred whilst rendering this message. Please contact the administrators, and inform them of this bug. Details: ------- org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getHtml' in class com.atlassian.jira.issue.fields.layout.column.ColumnLayoutItemImpl threw exception java.lang.NullPointerException at templates/jira/issue/table/macros.vm[line 117, column 34] at 
  

Steps to Reproduce

1. Create 1K+ links using a specific Issue link type;
2. Goto Administration -> Issue linking;
3. Delete the chosen Issue link type;
4. Before Jira finish processing the request create a new link using the link type being deleted;
5. Wait for the operation to complete;
6. Run the following query, a record with the deleted link type will be shown.

   select * from jiraissue where id in (select source from issuelink where linktype not in (select id from issuelinktype));
   

Expected Results

Jira was not supposed to allow users to choose the link type being deleted.

Actual Results

Users can use the deleted link type leading to data inconsistency;

Workaround

Use the workaround described in the following KB article:

• Error rendering 'com.atlassian.jira.jira-view-issue-plugin:linkingmodule'