It was very comfortable to use Greenshot for asking questions on SE since it could upload to imgur, which is the same hosting, used with SE.
Unfortunately, it started to respond with error 403 Forbidden on upload.
Is it possible to fix?
UPDATE
Tried to capture access to URL and found response:
<error>
<message>API limits exceeded</message>
<request>//2/upload.xml</request>
<method>get</method>
<format>xml</format>
<parameters/>
</error>UPDATE 2
I found that I still can use Greenshot from notebook. Notebook is behind the same NAT, so blocking issues are unprobable.
31 Answer
When using anonymous access to Imgur, you're affected by the global API limit for Greenshot. Which is usually depleted due to the large amount of Greenshot users.
You have to use an Imgur account with your own credentials to make the plugin work again.