Hi,
the demo bookmark implementation store a file with the bookmark info, and also the pdf path is stored in this file.
When you run the application on iOS simulator, the application path changes every time:
first run:
.../Library/Developer/CoreSimulator/Devices/19B59FBA-D11B-4400-99B2-17E38578ADB3/data/Containers/Data/Application/D41536FF-20F8-49D7-BA33-DB27658025C2/Documents/help.pdf
second run:
.../Library/Developer/CoreSimulator/Devices/19B59FBA-D11B-4400-99B2-17E38578ADB3/data/Containers/Data/Application/F5E4C498-927A-4AD2-AD4E-24DB16E6D76B/Documents/help.pdf
unfortunately in this case the pdf path is changed and the opening action returns an error message because is using the old pdf path.