FormatException Invalid Image Format

Verified: February 2020

Symptom

This error occurs late in the loading process or just after a city finishes loading:

• FormatException: Invalid Image Format: failed to load

In the full stack trace, which can be found in the log file, you might see one or more of these:

• AssetIcons.IconModifier.PatchIcons
• AssetIcons.IconModifier.OnLevelLoaded

Cause

This is caused by either of the following mods:

• Improved Asset Icons
• Improved Asset Icons (alternative)

Those mods also cause Object reference not set to an instance of an object errors.

Solution

Completely unsubscribe the mods listed above - they are game breaking.

If you need a better alternative, we recommend Find It mod which is extrmely reliable.

Fixed?

If not, let us know - currently the mods above are the only known causes of the error but it's possible there are other mods that cause it too.

Other issues? See: Troubleshooting