## Troubleshooting

- [What do the strange symbols on my mailing mean?](https://help.optilyz.com/en/support/solutions/articles/43000668324-what-do-the-strange-symbols-on-my-mailing-mean-)

- [Why are there stains on my postcard?](https://help.optilyz.com/en/support/solutions/articles/43000706576-why-are-there-stains-on-my-postcard-)

- [Loading issues on the optilyz platform](https://help.optilyz.com/en/support/solutions/articles/43000608466-loading-issues-on-the-optilyz-platform)

- [Why is the final price of my mailing different from the costs in the price calculator?](https://help.optilyz.com/en/support/solutions/articles/43000713168-why-is-the-final-price-of-my-mailing-different-from-the-costs-in-the-price-calculator-)

- [How is optilyz affected by the xz backdoor?](https://help.optilyz.com/en/support/solutions/articles/43000725833-how-is-optilyz-affected-by-the-xz-backdoor-)