Anyone else getting these weird error messages from Bing's spider?

[Biology Forums]

For the past week, I've been getting these errors from Bing's spider:



Notice that the error message is not shown and the links it's visiting have been removed in the past. Would could be causing this, and why isn't an error message available?

Sample links:

https://biology-forums.com/index.php?topic=471897
https://biology-forums.com/index.php?topic=121319

[Looking]

Have you looked at the links as a guest?

[Biology Forums]

Error is the same. Interestingly, when I get the error as a guest, it doesn't log.

[Bigguy]

I'm not getting any errors from Bing at all.