Hello, I had the same problem. Only, i only had the su-25a protect in the task manager... It was stuck and did not wanted to load... I tried repair, and starting up the computer again, but did not work.
Since the su25a_protect.exe also stayed there (i could not even shut the process down), i deleted all the aircraft modules manually (in the DCS World OpenBeta/Mods/Aircraft folder) except Su-25T and TF-51D. (You can try to install the modules again in module manager when it works again, but i have not tried this yet).
For me this makes DCS World Open Beta again, I have not tried to install the modules again, but maybe then it works.