Confluence Cloud Migration - Unable to communicate with server

[Julian Becher]

Hey folks,

we are trying to migrate Confluence Server (7.19.3) to Confluence Cloud using the official Cloud Migration Assistant. At the step to choose the cloud site it just loads for a while and then we get an error We can't communicate with your server:

The log on our Confluence Server shows a timeout:

2026-08-10 13:12:02,477 WARN [http-nio-8090-exec-1] [confluence.util.profiling.DefaultActivityMonitor] close Exceeded the threshold of 60000 ms: ActivitySnapshot{startTime=1786360022462, threadId=228, threadName='http-nio-8090-exec-1', userId='Julian', type='web-request', summary='/rest/migration/latest/cloud/generateCloudSiteSetupUrl'}
-- referer: https://confluence.xxx.de/admin/migration.action | url: /rest/migration/latest/cloud/generateCloudSiteSetupUrl | traceId: ef2533e819474613 | userName: Julian

We made sure that the firewall isn't the issue and allowed traffic for all domains listed here: https://support.atlassian.com/organization-administration/docs/ip-addresses-and-domains-for-atlassian-cloud-products/

I also tried downgrading the Confluence Cloud Migration Assistant and tried different versions, no luck.

Anyone experienced this issue?

Thank you

Julian

[Marc -Devoteam-]

Hi @Julian Becher 

Best is to raise an issue with Atlassian Support as they can see the migration that was running and also logging around the migration attempt.

On running all migration checks where there any warnings or errors?

Have you gone over the full migration pre-checklist, confluence-pre-migration-checklist