Issue Summary

Attachments when copy/pasted from other Projects or linked tickets shows Preview Unavailable or broken on create screen and comments. 

Steps to Reproduce

1. Copy an attachment from any ticket. 
2. Paste it either into the ticket from a different project (both Jira Software/Jira Service Management), a linked ticket. Either into the description or the internal or public comments. 
3. The spinning wheel keeps on rotating for some time and then throws the message, Preview Unavailable. On clicking on Save button it stays in the Preview Unavailable and on refreshing the page totally sometimes mitigates the issue and sometimes not.  
4. Checked with more than one browser, issue lies the same and also easily replicated in our test instances. 

Expected Results

The attachment on getting pasted should show the preview and work without any issue. 

Actual Results

The attachment shows Preview is unavailable. 

On saving it and then trying to see the preview, get to see. 

Workaround

So far only one workaround works, which is also not giving 100% positive outcome and that is refreshing the page.