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Below is a list of common issues that may come up when integrating the Collaboration Modules.

Cannot find module 'winston'#

Winston is listed as a peer dependency of @pdftron/collab-server, meaning it is not installed by default when running npm install. We list this as a peer dependency because we allow direct interfacing with our internal Winston logging mechanism, and if a project is already using Winston, then there would be two versions installed.

The fix#

Manually install winston

npm i winston --save

Errors related to resolvers#

If there are any errors coming from your resolvers, the issue is most likely that the wrong data is being read/written.

If you run into any issues like this, please try our resolver testing suite. This tool will report any issues with your resolvers.

Connecting to Azure SQL Databases with the resolver generator#

MS Azure requires encrypted connections when communicating with its resources. To enable this from the server, pass the encrypt: true option to the resolver generator:

import ResolverGenerator from '@pdftron/collab-sql-resolver-generator';
const resolvers = ResolverGenerator({
client: 'mssql',
connection: {
// ...other options
options: {
encrypt: true


For troubleshooting authentication issues, please see this guide.

Snapshots are not getting restored on other users screen#

This is intended! More information can be found here

Websocket connection timing out after X seconds#

If your users are getting disconnected after some period of inactivity, make sure any reverse proxies or firewalls are not timing out connections.

A common reverse proxy is NGINX, which disconnects connections after 100s. To fix this, add the proxy_read_timeout 36000s; setting to your location directive.