Can I use multiple EAs simultaneously?
This is possible, however it’s important to note that increasing the number of EAs and indicators on your platform will both increase platform load (potentially leading to laggy performance and crashes), and it may lead to confusion and errors in the performance of the EAs.
For example, if you have different EAs on your charts that are programmed to do similar things, and that send requests simultaneously, this can lead to an error message on your platform.
If you want to use the same EA on the same or multiple accounts simultaneously, it's best to download and install multiple instances of the platform you are using. This way the EA is only used once on each platform which reduces instances of platform lag and completely removes the possibility of confusion between EAs.
A guide on how to install multiple instances of the MT4 and MT5 platforms can be found in the “Running 2 Metatrader 4 platforms at the same time” section of this page.