I’m getting Errors

Each plan (package) is limited by a number of threads (simultaneous connections).

If you have a package with 40 threads and your software uses 41 threads, you will see errors and the proxies will not work. The same applies if you use the proxies on two servers: the total number of threads can't be higher than the maximum number of threads in your package.

Some software tools use a browser to perform automated actions. Each browser tab uses around 10 threads, because it loads images, JavaScript and other elements all at once.

With such software tools, you need to lower the threads in the software and upgrade to a bigger package.