Hello @PeterFredericks and welcome to the community!
I understand that the program that you purchased is being blocked by the Trend Micro program, May I ask if you can post a picture of the detection that is shown to you on this thread so that we can better check why the program is being blocked by the Trend Micro program.
One possible explanation why the program is being blocked by the Trend Micro program is that it is considered a Malicious program. The Trend Micro program blocks threats that may give out sensitive information or that can cause damage to your computer.As upon checking with reliable sources the JustCloud program is a Potentially Unwanted Application, these Potentially Unwanted Application sometimes download malicious files over the internet or they disable the security program installed on your computer. We would need to know the detection of the Trend Micro program so that we can check on our Threat Encyclopedia the type of threat that is being detected and what it does to your computer.
Thanks so much for posting here in our Trend Micro Community and wish you have a great day!