If you find the spin light flashing at end of the cycle and the laundry is still wet (hasn’t been spun), the explanation could just be that the washing machine’s out of balance protection system prevented it from spinning. This is particularly true for the following Hotpoint washing machine models WMA30, WMA31, WMA32 & WMA33, and could potentially apply to some other models.
Before going into a fast spin, all washing machines go through a distribution cycle to settle the laundry down and distribute it evenly around the drum. If it manages this ok it will kick into a fast spin. If the drum isn’t balanced properly though, a spin can cause violent movement which could seriously damage the machine, so most machines will not spin if they think the load is unbalanced.
Any decently designed machine should indicate to the user that this is what has happened instead of leaving them thinking the washer has broken down. Some do it better than others, check your instruction book to see what indicator your model uses for showing it couldn’t balance the load for a spin. Some may use a red light flashing but others may use a totally different method.
To fully understand this out of balance system read my article here – washing machine won’t spin just one item or very small loads
Related: If the washing machine is just not spinning any load, as opposed to a one off or occasional incident described above, check this article instead – Not spinning at end of cycle