I am new on Hammer Editor and wanted to add some doors and transparent glass but I didn't know how so I looked up a tutorial on Yt.I followed what the guys said(It was pretty hard because the guy was constantly chewing gum into the mic).I built the doors and glass but when I went to run the map.It said there was a problem.After that I went to the map category and I checked for problems,there where a bunch of them but they got fixed except of the glass and door one.I will add the tutorial so you can see if the tutorial had something wrong.When I opened the "Check map problems" tab the problems said:for the door-Solid entity(func_door rotating)is empty with the decripction that said:This solid entity contains no solids;for the glass-Solid entity(func_wall)is empty with the decripction that said:This solid entity contains no solids
There is a function called func_door, this function creates the door from the brush you have set. ( func_door_rotating or func_rotating for a rotating door, requires another brush with origin texture as the axis base ). For an invisible glass, set the brush to func_wall ( func_breakable if you want a breakable glass. ). Scroll down and find the Render Mode and set it to Texture. Then, find the FX amount and set the value you want to make an invisible glass with ( Maximum = 255, example: use 100 as the FX amount ). Also works with most func_ options.
Try using all this above and you shouldn't end up with any error ( at my end ).