Thanks for replying again. Luckily since clicking the X to reset directory seems to solve it, it has worked for me everytime a map has ran into this. My theory is if I add too many or remove too many meshes then it will inevitably occur. (I use the replace existing meshes option but the crash will occur without it as well)
Since I know this avoids the problem its not the worst thing ever but it does kind of suck to have everything crash on import "randomly". Sometimes the map will be importing consecutively and then this pops up. If you need any other kind of information potentially let me know I am always down to help.
Even with such a problem I would just like to add that HAMMUER has been game changing for working on Unreal Engine projects and has really changed how i work on level design and even given me a lot of extra motivation to keep working at it. Thanks for building such a great tool <3