Hi. Heres a simple instruction for people who getting "failed to open action manifest" error:
1. Open GMod and enable VRMod addon
2. Start new singleplayer game
3. Open console, type "vrmod_bindingversion 0;lua_openscript_cl vrmod/vrmod_steamvr_bindings.lua" and press Enter

For some reason, VRMod indicates that the files have been created and does not recreate them, which is why they simply do not exist. Have a good game!

P.S. if you wanted to check if files created, search for "vrmod" folder in "garrysmod\data"