I found that if you use the mRemoteNG for a long time (4 hours and more) and that you copy a lot of stuff between a workstation and a server for example that for some unknown reason the rdpclip.exe on the server is leaking for memory and the process can take all the memory of the server and the server will hang... Yes I crashed a server with mRemoteNG I did some tests and I found that it isnt one server. I saw it on 3 differents servers and I was lucky to find it before the server crashed and I killed the process.
Maybe you can disable by default the copy function and add an option for that.
If I use the RDP version of Microsoft on my server I don't get a problem like that but I like your product and I hope you will correct it.
Please note that I can replicate this problem 4-5 times a day...