Embedded sheet not displaying in Firefox Quantum

Embedded sheet not displaying in Firefox Quantum

After the last update of Firefox (57.0), embedded sheets do not get displayed; Firefox starts using too much CPU and fills all system memory (8GB).

For test you can look at my page: http://kadifeli.com/fedon/bordro.php
To replicate the problem you may have to reload the page a few times.

When I login to Zoho and try to edit the same sheet in https://docs.zoho.com/ I do not have the same problem.

I restarted Firefox in "safe mode" and the same problem persists.

Note: I am running Firefox Quantum 64-bit under Windows 7. Chrome 62.0 does not seem to exhibit this problem.