@heraclito2077: If that was you who emailed us, your debug output doesn't include the full save attempt. Can you try again, following the instructions carefully?
But if you can't submit the debug output, I'd guess that your network requests in Zotero aren't working generally. E.g., are you able to use Add Item by Identifier to add an item (e.g., 0838985890)? If that's the case, see Connection Error. You'll need to fix your network connection in Zotero before this or various other features will work.
well, i have a proxy,maybe this is the problem; i do not understand the setup of the proxy, i do not understant the following: %h.example.com/%p . My proxy is: proxy.sld.cu and the port is 3128
The proxy settings in the Zotero Connector are unrelated to Zotero itself. See the Connection Error page for the things that affect Zotero. If you have an IT department, I'd recommend asking them for help with this. Zotero will automatically use the system's proxy settings, but if you have a more complicated setup you might need to make manual changes.
Upgrade Storage
This does work on PubMed Central.
in this moment i am trying to download this article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859834/ but i can't download the pdf.
But if you can't submit the debug output, I'd guess that your network requests in Zotero aren't working generally. E.g., are you able to use Add Item by Identifier to add an item (e.g., 0838985890)? If that's the case, see Connection Error. You'll need to fix your network connection in Zotero before this or various other features will work.