Have you maybe got more information on that error message? And are you sure all features you are trying to dissolve are the same (valid) geometry?

I checked the geometry by using the GeometryValidator and AreaGapAndAreaOverlapCleaner on my dataset (as we can see in the orange bookmark). But maybe it's not enough to correct topological errors ?

Otherwise I don't know how to have more information about the error message than what we can see on this picture.

Looks like you've encountered an unexpected problem, perhaps even an exotic bug. Some strategies to try:

• Try the most recent (or a different) version of FME.
• Insert an AttributeKeeper just before the Dissolver and make sure to only select the indispensable attributes
• Insert a GeometryValidator before the Dissolver and try to exclude problematic geometries to see if that makes a difference
• Enable debug messages in the FME log (FME Options / Translation / Log message filter) and look for messages just before the error occurs
• Try both with Feature Caching on and off
• Try inserting a Decelerator set to 0 just before the Dissolver

I recommend trying these things one by one. Perhaps also consider opening a suppor case with Safe through your FME reseller.

I controlled the topologicals errors in ArcGis Pro and there still have gaps and overlap even after the GeometryValidator and the AreaGapAndAreaOverlap transformers. I don't know how I can correct them in a other way.

I would try modifying the Tolerance value - try 0 and a something like 0.1 or higher to see if it has any effect - If the workspace takes a while you should disable the problem transformer(s) to fill up the initial caches before you change the values to save on processing time.

I've had experiences with other Transformers which crash depending on the tolerance setting (e.g., GeometryValidator trying to Repair features).

You should also take a look at the Tolerance in the GeometryValidator under Self Intersection - Try setting this to 0 to see if identifies new problem features.

If you are able to isolate the problem feature(s) and send a reproducible problem to Safe support I'm sure they'd appreciate it.

Yes I saw that but I also saw the Snapper transformer after the GeometryValidator. My experience with snapping transformers is that they are prone to bring issues like self-intersections into your data if you dont closely monitor the Tolerance settings.