Unable to refresh or load new data - Syncing schema infinite loading

[llcsl]

Hello!
For the last week I'm having a very weird issue and I can't get help anywhere, I don't know if it's a new issue or simply no one ever got this kind of error.

Every time I'm trying to load a new query to my existing .pbix file I get a syncing schema message during load that does not end. The same happens when trying a local refresh:

This is what happens when I try to add a new data source. And I really mean ANY, even if I try manually inserting data directly to PowerBI.

This happened while trying a local refresh.
While looking at Process Manager I monited the SQL Server Analysis process was slowly raising, until it got to this point:

My local IT support does not have any info on how to solve this and neither do I.

Everything loads fine on the Power Query or on a blank file, this happens only on my existing file.

Steps I already tried to debug:

• Tried adding different data sources
  • Error
• Tried adding a source already existing on the file:
  • Error
• Tried adding local data source
  • Error
• Tried manually adding new data
  • Error
• Refresh the whole table
  • Error
• Refresh single table
  • Error
• Older file version, from before the error started
  • Error
• Rollback PowerBI version
  • Error
• Update OBDC driver
  • Error
• Clear all credentials and configure them one by one again
  • Error

I can't provide the file because it has sensitive data, but I'll try any possible fix you can suggest me.

[llcsl]

Hello guys, sorry for taking too long to reply.
I tried @amitchandak approach, sadly it didn't work.
Also @MichaelVenables solution didn't work, clearing the credentials also didn't help.

Just like @CPCARDOSO said, it's the schema that's way too complex and things got out of hand. I was able to open it again TODAY, by going back to PowerBi May/25 version, way before the refresh dadta/schema/both update.

It's just too slow to work in the file, which is clearly a poor data modeling issue. We're currently planning the refactor of the semantic model

In any way, thanks everyone.

[MichaelVenables]

Hi,

Just wondering if this is an issue where you need to clear your login credentials then log back in again as i have had this happen in the past.

I imagine you have already tried this but if you go to data source settings and clear all permissions then login again. Then try to refresh this data.

Thanks,
Michael

[v-sgandrathi]

Hi @llcsl,

Thank you so much for your replies in this query @CPCARDOSO and @amitchandak.

I wanted to check if you had the opportunity to review the information provided by community members. Please feel free to contact us if you have any further questions.

Thank you and continue using Microsoft Fabric Community Forum.

[CPCARDOSO · Accepted solution]

Olá @llcsl, 
O erro “Syncing schema” sem fim no Power BI geralmente ocorre devido a inconsistências internas na estrutura do modelo, acúmulo de metadados obsoletos, problemas de memória durante operações de carga ou transformações avançadas no Power Query. Isso pode ser agravado por queries complexas, múltiplas dependências, ou mudanças recentes de colunas/tabelas.

Recomendações Práticas

1. Backup e Experimentos Seguros

Sempre trabalhe em uma cópia do arquivo original antes de testes destrutivos.

2. Diagnóstico Sequencial

• Verifique se há passos no Power Query que dependem de colunas/tabelas removidas. Refaça os passos finais (“Changed Type” é frequente causador).

• Elimine ou ajuste merges e appends complexos, teste o comportamento removendo um a um.

• Execute “Remover Linhas/Colunas Não Utilizadas” em todas as queries.

3. Reduzir Consumo de Memória

• Remova tabelas e colunas desnecessárias.

• Se possível, filtre os dados na origem para baixar o volume antes de carregar

4. Forçar Reset do Modelo

• Copie todas as queries em Power Query (Editor Avançado).

• Cole as queries em um novo arquivo .pbix em branco.

• Refaça as relações e medidas calculadas para isolar se o problema está nos metadados do modelo original.​

5. Referência Oficial

• Guia de solução de problemas de refresh: https://learn.microsoft.com/power-bi/connect-data/refresh-troubleshooting-refresh-scenarioslearn.microsoft​

[amitchandak]

@llcsl , I saw a similar issue shared by another user too. 
First, try the refresh meta option, followed by refresh meta and Data. If that does not work, please log and issue - https://community.powerbi.com/t5/Issues/idb-p/Issues