Trouble downloading metadata and covers

[Deep Cover]

I'm loving Calibre and have been using it for quite a while, but I've been running into some problems recently. I tried searching the forum for it, because it seems like the sort of thing that's come up before, but no luck.

Here's a typical example of the error message I get after clicking the "download metadata" button:

calibre, version 1.28.0

Traceback (most recent call last):
File "site-packages/calibre/utils/ipc/simple_worker.py", line 51, in run
File "site-packages/calibre/utils/ipc/__init__.py", line 19, in eintr_retry_call
EOFError

And I get the same thing when I try to download covers:

calibre, version 1.28.0
ERROR: Download failed: Failed to download any covers, click "Show details" for details.

Traceback (most recent call last):
File "site-packages/calibre/utils/ipc/simple_worker.py", line 51, in run
File "site-packages/calibre/utils/ipc/__init__.py", line 19, in eintr_retry_call
EOFError

The funny thing is that it worked just now with the same record, and the only difference (I think) was that I had the "view log" window opening as the download was running. But then I tried the same trick with another record, and it didn't work.

Any ideas?

[kovidgoyal]

Something on your computer is causing the worker process calibre uses to crash. Most likely some security software.