Hello.
We have reproduced the same problem in CA lab using webservices_rest 8.5.1 HF3.
If you are using webservices_rest 8.5.1 HF3, please do the below
1-1. deactivate wasp probe in UMP robot.
1-2. Remove "wasp-engine" folder in <UIM>/probes/service/wasp/work in UMP robot.
1-3. deploy webservices_rest 8.5.1 (GA release) onto UMP robot.
1-4. activate wasp probe in UMP robot.
1-5. Use the below URL encoding for Target name.
C%3A%5C%2FFree%20(in%20%25%20of%20Capacity)
Some website helps you to get URL encoding.
Here is an example.
https://meyerweb.com/eric/tools/dencoder/
Regards,
Yu Ishitani