My LTSCALE in drawings is set to 1 but for a DASHED line to show i have to change the property LTSCALE of that layer to 300.
 
For this to happen in previous drawings the LTSCALE was set as 1 but the property LTSCALE of the DASHED layer only has to be 0.5
 
Can anyone tell me what is wrong with the SCALE?
 
Regards
 
Chris

Is this all occuring in Modelspace?
perhaps one drawing is set up to be metric, so it uses acadiso.lin vs acad.lin for linetypes..check MEASUREINIT settings.
 

The dashed line is also affected by annotative scale, just in case you use it.