We've recently made a change to our application and unfortunately some browsers are still holding on to the old information.
deleting browsing history, you can leave your saved passwords, just need to
refresh the cache and delete the cookies.
If still an issue try using WPM in Incognito mode (Chrome: Ctrl + Shift + N) or Private Mode (Firefox: Ctrl + Shift + P) - these modes don't use your cache or cookies.
If that hasn't fixed it, please create a support ticket and we will get right on it.
Delete Browsing History in Chrome:
With Chrome open, go to the top left and click the three little lines. Select Settings. Top left click History and then click Delete Browsing History…and then select cookies and cache items to delete. (you can leave Passwords un-ticked).
Close Chrome and then re-open.
Delete Browsing History in Firefox:
With Firefox open, go to the top left and click the three little lines. Select Options. Left hand side click Privacy and then click "clear all current History". From the dialog box select all items and click Clear Now.