Can't view documents

[ScrumpyJack]

Roundcube 1.4.8
Cloudview latest
Firefox 80
PDF works but docx returns an empty page with "about:blank" about 50% of the time, which is strange. Closing the "about:blank" and clicking on the attachment again and it works. Nothing in the logs

[jfcherng]

In my vague memory, I seemed to encounter this in Chrome too. But I can't speak what causes this or whom is to blame... It seemed to just happen randomly even with a same link.