I am having a similar error, I am unable to sync the data. And I am getting an error message of unablr to connect to server even with active internet. Let me know how to fix it.
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "Error connecting to server. Check your Internet connection."]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
Upgrade Storage
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "API key not set"]
[JavaScript Error: "HTTP GET https://api.zotero.org/retractions/list failed with status code undefined"]
[JavaScript Error: "HTTP GET https://api.zotero.org/retractions/list failed with status code undefined"]
[JavaScript Error: "HTTP POST https://repo.zotero.org/repo/updated?last=1563816900&version=5.0.72&m=3 failed with status code undefined"]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "Error connecting to server. Check your Internet connection."]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "HTTP GET https://api.zotero.org/retractions/list failed with status code undefined"]
[JavaScript Error: "HTTP GET https://api.zotero.org/retractions/list failed with status code undefined"]
[JavaScript Error: "HTTP POST https://repo.zotero.org/repo/updated?last=1563816900&version=5.0.72&m=1 failed with status code undefined"]
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "NetworkError: A network error occurred." {file: "chrome://zotero/content/xpcom/openurl.js" line: 52}]
discoverResolvers@chrome://zotero/content/xpcom/openurl.js:52:5
Zotero_Preferences.Advanced.populateOpenURLResolvers@chrome://zotero/content/preferences/preferences_advanced.js:414:30
oncommand@chrome://zotero/content/preferences/preferences.xul:1:1
[JavaScript Error: "NetworkError: A network error occurred." {file: "chrome://zotero/content/xpcom/openurl.js" line: 52}]
discoverResolvers@chrome://zotero/content/xpcom/openurl.js:52:5
Zotero_Preferences.Advanced.populateOpenURLResolvers@chrome://zotero/content/preferences/preferences_advanced.js:414:30
oncommand@chrome://zotero/content/preferences/preferences.xul:1:1
[JavaScript Error: "The connection was refused when attempting to contact wss://stream.zotero.org/." {file: "chrome://zotero/content/xpcom/streamer.js" line: 155}]
[JavaScript Error: "WebSocket connection closed: 1006 "]
[JavaScript Error: "Error connecting to server. Check your Internet connection."]
version => 5.0.72, platform => MacIntel, oscpu => Intel Mac OS X 10.14, locale => en-US, appName => Zotero, appVersion => 5.0.72, extensions => Zotero LibreOffice Integration (5.0.20.SA.5.0.72, extension), Zotero Word for Mac Integration (5.0.24.SA.5.0.72, extension)