unit systen 3dsmax

yes i have change the unit setp- US standard -feet- 1/32... the result is same.

US standard-decimal feet

yes panthom . i changes . please have a look . https://ibb.co/ygy00dS

I don't see a problem here, i created a box wich is 13ft in height and it looks exactly the same as your screenshot. Than I measure some of mine models that are 100% accurate dimensions wise and dimensions reading are correct in feet.

yes i have already chk it , now you need to see this . you will understand my problem https://ibb.co/1G8WY82 https://ibb.co/yqDMk8d

This must be out of scale. https://ibb.co/1G8WY82 , if that blue box on other screenshot is 13ft long

3d cargo here is a link https://ibb.co/ygy00dS and yes i have reset , i think the problem is not in system unit , because in feet and Cm both are givving the same result. think how can 12 feet wall so long ?

I think you may be correct about the system units not being an issue - it shouldnt be an issue unless you are merging 2 files with different units. Now regarding your issue, whats wrong with a 396 cm wall? Its hard to know what you are making do you have the drawings/plans available to look at?

yes let me show you . https://ibb.co/1G8WY82 https://ibb.co/yqDMk8d its a small exterior house .

Looks like you have 2 problems. Problem 1: Check that your imported floorplan is to the correct scale, door widths are usually 80cm or 90cm. Problem 2: Where are you getting this information of the wall being 13foot? Which wall? The easiest way fix all your problems at once is simply measure one of the walls in CAD, then bring this into 3dsmax and make sure that same wall is the dimensions you just measured.