In this situation, we would suggest you try the following options:
On Pocketmags.com (reading in your browser):
Exit the issue, then re-launch. Also try pressing CTRL+SHIFT+R to hard refresh the browser.
On one of our apps:
Please try to delete and redownload the issue. To delete the current download please go to My Library and then tap the 3 dots by an issue and select Delete (alternatively use the bin icon in the top right, then select what you want to delete and confirm). Once this is done exit the app, re-open and then try to download again.
If you continue to experience problems, please contact us at help@pocketmags.com with details of the problematic issue and we will be happy to investigate and assist.