Ebook viewer: unhandled error when clicking "Show viewer controls"

[Francisco Pombal]

Calibre version: 5.1.0
OS: Ubuntu 18.04 with the latest updates

I get the following error when clicking the "Show viewer controls" button in the Ebook Viewer.

calibre, version 5.1.0
ERROR: Unhandled error: Uncaught TypeError: Cannot read property 'metadata' of undefined<br><span style="font-size:smaller">Error at userscript:viewer.js:38311:226</span>

Traceback (most recent call last):
    at IframeWrapper.handle_message (userscript:viewer.js:16036:17)
    at View.on_report_cfi (userscript:viewer.js:41893:17)
    at View.do_show_chrome (userscript:viewer.js:41051:30)
    at Overlay.show (userscript:viewer.js:38917:18)
    at Overlay.show_current_panel (userscript:viewer.js:38907:69)
    at MainOverlay.show (userscript:viewer.js:38311:226)
TypeError: Cannot read property 'metadata' of undefined

This happens every time. I tried restarting Calibre and restarting my machine.

Steps to reproduce:

1. Start Ebook Viewer
2. Click the "Show viewer controls" button.

See the attached screenshot.

[Kovid Goyal (kovid)]

Fixed in branch master. The fix will be in the next release. calibre is usually released every alternate Friday.

 status fixreleased

[Francisco Pombal (pombal.francisco)]

Thanks for the quick fix Kovid!