Hello, sorry you are having these difficulties. I am not sure why your modal study was able to mesh, you should compare mesh settings and note any differences. The defaults for LSS and Modal are the same so I would expect them to mesh the same if you are using the same settings.
The meshing errors you are showing indicate modeling issues. There is a repair tool in the Design environment but you need to ensure that "Capture Design History' is disabled. Right click on the root of the browser to see this option, it may already be disabled if your geometry was imported from another format. You will then see a 'Validate' command under the Inspect menu. The can be used to repair bodes automatically, unstitch bad faces so you can replace them, and remove very small faces/edge which the mesher may not be able to cope with. I highly recommend making a copy of your document and experimenting with this command there, then once you have gotten the hang of using this tool and made some progress with the model, you can make the repairs on your original file.
You can also try using a smaller mesh size since your parts are very thin, but keep in mind this could slow down the analysis if you make the size too small.
I hope this helps, good luck!
Rob McMillan
Software Architect, Fusion Simulation
Autodesk
Fusion
