Dashboards not uploading nor displaying

[malikirfan28]

Dear Experts,

We were using Power BI Embedding using Azure Workspace Collection  which we are migrating to new Power BI with Capacity flow. We have about 400 dashboards and after setting up everything on Azure side, I subscribed Power BI Server (app.powerbi.com) as trial  and start uploading dashboards into App Workspace. All Dashboards are using "Import" data (no direct query). After uploading couple of dashboards, I tried to upload one big dashboard (1.1 GB in size). In Azure Workspace collections we were not able to uploadin this big dashboard (so I was testing it here.

Anyhow I recieved error when uploading this big dashboad that some Internal Server error occured so tried again after some time. After this error, I am neither able to view (already uploaded) dashboards nor able to upload any new dashboard in App Workspace. 

When try to view any dashboard then getting following error

I deleted all uploaded dashboards and all datasets and even deleted "App workspace" and created new Workspace. But still I am not able to upload dashboard in new workspace and getting following error

I am not sure, what went wrong and how can I fix it. Please need your expert openion. 

Thank you in advance.