I’ve just upgraded the RAM in two iMacs requiring adhesive strips and had a problem both times. In the first, the white tape on the lower part of the ‘3’ strip broke leaving about 50% behind.. In the second, both ‘2’ tags came off the white tape leaving all the tape still attached to the sticky layer. Both these instances caused a major problem as part of the screen was already stuck down. I had to try to make a gap between the screen and the case to insert a craft knife to loosen an edge of the white tape so I could grab it with my tweezers. Nightmare! Perhaps the adhesive strip kits sold in Europe aren’t as good quality as the ones sold in the US.