If the organisation logo is over 500 × 500px, this can cause an error message when marking evidence.
Please check the dimensions of the Organisation logo. If it exceeds 500 × 500px, try uploading a logo that is equal to, or smaller than 500 × 500px, to see if this resolves the issue.
Please note that this change typically takes up to 24 hours for the caching to clear and the new logo to be seen on all docs.