The game requires texture resolutions to be a power of 2, like 128, 256, 512 etc but at least to be a multiple of 4 for compressed texture formats. If a texture with an unsupported resolution is used directly it typically causes CTD.
Typically the game supports up to 8192 (DirextX 9, Skyrim) or up to 16384 (DirexctX 11, Skyrim Special Edition) resolutions for a single texture.
The maximum possible resolution of textures generated by DynDOLOD can be reduced by changing the setting MaxTextureSize at the ..\DynDOLOD\Edit Scripts\DynDOLOD\DynDOLOD_[GAME MODE].ini. Typically the size of textures added to the object LOD atlas textures or tree LOD atlas textures should be controlled in the advanced mode.
The maximum possible resolution of textures generated by TexGen can be reduced by changing the setting MaxTextureSize at the ..\DynDOLOD\Edit Scripts\DynDOLOD\TexGen_[GAME MODE].ini. Typically the resolution of the generated textures should be controlled via the TexGen options window.
Object LOD supports multiple object LOD atlas textures per worldspace. In case all available space on an object LOD atlas texture is used, additional ones will be created and used automatically.
Standard tree LOD only supports a single tree LOD atlas texture per worldspace and a maximum of 256 billboards. In case there is not enough space for all the tree LOD billboard textures to fit onto the tree LOD texture atlas, resize some tree LOD billboards (use lower settings in TexGen) or lower the max tile size billboard in the advanced mode. Alternatively use ultra tree LOD.
Determine Sensible Texture Resolutions
When TexGen generates textures, their resolution varies for each depending on their type, the TexGen settings and the TexGen configuration.
Raising settings without any understanding is wasting resources and performance without any visual improvements. There is typically no visual gain using higher texture resolutions for lower screen resolutions. VRAM is wasted for texture resolutions that are never used with default mipmap bias.
The configuration and resource files are set to work in combination with the TexGen settings which roughly relate to the vertical screen resolutions as indicated. This is normally not true for full textures used by full models, but in case of LOD models and textures and especially for tree/grass LOD billboards it just happens to work out that way.
Testing of texture resolutions is done for the vanilla game with default FOV and some popular new world and other mods. Higher FOV means textures require less resolution and vice versa.
It is possible to visually check in game if textures have suitable resolutions by marking the largest mipmap of the texture atlasses in a solid color. Game engines fade between mipmaps, so the more this solid color a texture becomes the more the largest resolution is used.
Add MipMapTests=1 to ..\DynDOLOD\Edit Scripts\DynDOLOD\DynDOLOD_[GAME MODE].ini right under the [DynDOLOD] section header in order to paint the largest mipmaps of the texture atlasses with the solid color red. When testing in game, any object LOD and tree LOD model that doesn't turn red just before being switched to the full model does not benefit from the largest texture resolution. Keep in mind that many different LOD models may share the same texture, so it is quite normal for many things to never turn a shade of red.
Add MipMapTests=-1 to ..\DynDOLOD\Edit Scripts\DynDOLOD\DynDOLOD_[GAME MODE].ini right under the [DynDOLOD] section in order to add one additional larger mipmaps (as if the texture resolution were increased one step) with the solid color red. When testing in game, any object LOD and tree LOD model that turns solid red would really benefit from a larger texture resolution.
To test a specific LOD texture generated by TexGen, replace it in the TexGen output folder with a texture that is solid color green for example. That will make it easier to spot the LOD that uses that texture and as long as the LOD is green, its resolution is sufficient.
Keep in mind that TexGen is not able to update all object LOD textures in the moment. Especially far away mountain rocks, icebergs and glaciers are typically using (low resolution) vanilla rendered object LOD textures, unless a mod provides them.
Remember, the final resolution of a texture on the texture atlasses is limited by the actual resolution of the source textures and the maximum tile size set by the advanced options of DynDOLOD.
There is typically no point in raising the texture size Min of billboards as long as the units per pixel is used as intended. Especially grass LOD billboards rarely require resolutions beyond 32 pixels, which should be obvious considering the height and distance of grass LOD.
In case there are occurrences of specific textures generated by TexGen which could benefit from a larger resolution by default, consider making a post about it on the official DynDOLOD support forum.