Re: Some beams show red error when getting beam detail Hello The TBDY 7.4.3.1 check may be left ticked on the beam parameters screen. When this check is done; TBDY Article 7.4.3.1 beam clamping length control (ab) error exists in the beams stuck to the curtains in the short direction. If you do not want this check done, the option can be disabled. If you uncheck this check is not performed. Earthquake regulations exempt simple beams from this control. However, there is no such exemption for beams connected to the walls from a non-rigid direction and it is not clearly stated in the earthquake code. In order to control TBDY 7.4.3.1, I suggest you to analyze with option active (checked) and provide the following solution methods and conditions. 1-Generally, the most appropriate solution would be to reduce the diameter of the largest reinforcement used in the beams in order to provide the "a" distance in the beams inserted in the short direction into the shear walls in your project. When large reinforcement diameters are used, control may not be achieved because the lb distance will increase. In your project, max. The condition can be met by using Ø12 reinforcement diameter. 2-Increasing the concrete class 3-Increasing the wall thickness may be other solutions. In 10.59 version of TBDY Article 7.4.3.1, you need to get the beam details of all floors or get a quantity report after the analysis in order to perform the ab control. It is among our notes that it is necessary to take beam details to perform ab control (interlock length control).