Stack Overflow Error Appending Queries

[Anonymous]

After trying to append two queries together I receive the stack overflow error. I tried to follow the steps described here  https://superuser.com/questions/1193926/stack-overflow-error-importing-data-to-microsoft-power-bi-ev... but I cannot find either Microsoft.Mashup.Container.NetFX40 or ValidationException values. is there anyone who can help me?

My 2 appended queries have the same amount of rows, about 500k.
Thanks in advance.

[v-chuncz-msft]

@Anonymous 

A similar issue has been reported internally, so stay tuned. You can call Table.Buffer on each of the tables being combined before calling Table.Combine.

CRI 224968762

[Anonymous]

Hi @v-chuncz-msft I've called Table.Buffer before Table.Combine.

F_Sales=(Table.Buffer(Table.Combine{F_sales_b,F_sales_1})) but unfortunately it doesn't work.

In addiction, I cannot refresh preview in power query, in my Query list those tables have the Alert sign. 

What can I do?