In order for the i1iO or i1Pro to correctly read testcharts in Strip mode, the device needs to be able to clearly "see" the separators between each patch. Certain printing workflows like screenprinters or UV printers, or printers using highly textured substrates may find that their testcharts are too grainy or uneven for to read successfully in strip mode.
If you are experiencing this problem there are a couple of options to address the issue. First, if you are using Colorport, go to Properties under Measurement Device and increase your patch size, and/or your patch separator size. Then, under Default Layout choose Customize and select the checkbox to Scramble your patches. You may have to experiment with these settings to find the ideal combination for your process. If all else fails, you can use the i1Pro to read in Patch mode with Colorport and Monaco Profiler.
If you are using i1Profiler, ProfileMaker or i1Match, you can measure your testcharts in Patch mode to eliminate this problem.