Hi new to the group and looking forward to sharing experiences. We put in the 16' round radiant metric pool in 2016 and this is first problem we had. We too just took off winter cover to find liner detached and water behind it around half of the pool. We sucked the water out with shop vac and it seems to work. We re-attached liner to coping and will buy liner lock ASAP. Much appreciation to learn there is a fix although it would have been nice to know this could even happen! I will order from Amazon on Monday. I knew there would be a chat group discussing this. THANK YOU!