If you are getting below error while installing Wordpress Toolkit from WHM Marketplace and also you are not getting any specific error log which can help to resolve the error.
In this case you have to restart cpsrvd process :
This command will help you but if you are still getting this issue then you can install Wordpress Toolkit manually.
Code:
Error: There was a problem with the install. Refresh the page and try again.: [object MessageEvent]
Code:
/scripts/restartsrv_cpsrvd –hard