I am encountering an issue with running my test class as a made-up user. It seems like I have insufficient access to uploading files onto the org, anyone would be able to point me in the right direction? The profile has a Customer Portal license I already tried enabling the Select Files from Salesforce on the profile system permissions I already tried allowing guest access to upload files
You have multiple types of error there.
DUPLICATE_VALUE is an error on inserting a Hierarchy Custom Setting that already exists.
INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY is an error that can be generated by a myriad of different issues. In this case, my first guess is that the running user does not have access to the record to which you are seeking to attach the file.