"temperature of external wal did not converge" error in TRNSYS

edit

What type of wall construction do you use? Which boundary conditions does it face?

Does the same error message occure when you use a different construction for this zone? Have you tried to plot the outside temperatur of that external wall on a online plotter? It seems that the wall is facing high loads (either external or internal) which stack up over time.

General things to check: - thermal properties of the layers and materials (e.g. conductivity) - Time base setting as deafult (1) - internal loads and gains

Does the same error occurs when you set an outside boundary condition e.g. 20°C for that wall