Unable to create backup, access is denied

[Jackf99]

I created a workflow to automate a finance process. I output multiple files to different sheets in a excel file and use blob to format some sheets in the file. I am getting the error unable to create backup, access is denied even though I use block until done tools throughout. The thing that is really confusing me is that sometimes the workflow works and other times I get 1 error.

Here is the workflow,

[Jackf99]

Workflow