Hi, I can investigate the warning message you are getting, but how many trades open will depend on your settings and it is not a bug in the system. Please share your cBot settings as a text file uploaded in a post and a description of the steps you are following to get the warning.
Please note the BeginInvokeOnMainThread is a warning and not an error, it will not affect the performance of the cBot.
Also, please provide a screenshot of the cBot log showing the version number.