Following on from above, I logged a Direct Support ticket and through the help have resolved the issue. The major issues are low drive space on the 😄 (where the user profiles are, which is where IniManager downloads things too) and having the AV on whilst trying to download. I tried IniManager 2.3.7 on a different computer with more available drive space, disabled AV and it ran to completion.
I must also say many thanks to the support staff who were very helpful with getting through this.