How to solve cookie/cache problems

If you have difficulty trying again after an unsuccessful registration attempt, you can
follow these recommendations:

Using "Private Mode" in the browser
When using the "Private Mode" (also called "InPrivate", "Incognito" or "private browsing") no data is loaded into the cache and no permanent cookies are written. The need to clear the browser cache is therefore eliminated.

The "Private Mode" can be started by the following key combination in the respective browsers:
⏵Edge [Crlt]+[Shift]+[N]
⏵Firefox: [Crlt]+[Shift]+[P]
⏵Chrome: [Crlt]+[Shift]+[N]
⏵Apple Safari: [Command]+[Shift]+[N]

Alternatively, the "Private Mode" can also be started via the menu control of the browser.

Clear the browser cache (if "Private Mode" is not used):