Read the error message and check the log above the exception for additional hints. Check the list below for additional explanations for some exception messages.
Always use the the latest version of DynDOLOD/TexGen.
Follow the installation instructions and do not install tools or the game into special Windows folders like Program Files, Game, Data or mod manager folders to avoid issues with files access etc.
Finalize the load order. Install mods, sort and resolve conflicts. Clean and error check the load order with xEdit. Clean every plugin that LOOT suggests to clean - ignore misinformation that cleaning any plugins is not needed or causes problems. While ITMs are irrelevant in this context, see There are no intentional ITMs. The Batch Plugin Cleaner for Mod Organizer or the xEdit Cleaning Extension for Vortex help to automate some of that. Check the load order for errors with xEdit before generating LOD. Fix all errors. See this video for help (ignore the old cleaning instructions as that was already done).
Check FAQ answers for High memory usage.
Search the official DynDOLOD support forum for the message to find discussions about the same topic, especially if the exception message is not listed here but also for additional discussions.
If the problem persists, post an error report with the log, debug log and bugreport.txt as explained to the official DynDOLOD support forum.
Access violation
Always use the latest version of DynDOLOD/TexGen as explained above.
This could be caused by invalid or corrupt assets.
This could be caused by invalid or corrupt plugins. Check the DynDOLOD log for unresolved form ID and Ignoring Cell error messages in particular. Clean and error check the load order with xEdit. Fix all unresolved form ID errors in particular.
This could be low or out of memory problems. Check memory usage in Windows Task Manager. Let the OS handle page file / virtual memory automatically. Check FAQ answers for High memory usage.
This could be unstable hardware, like CPU, memory, cooling or overclocking etc.
This could be caused by the OS or antivir interfering with file access.
This can be a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Assertion failure
Always use the latest version of DynDOLOD/TexGen as explained above.
If the assertion failure is a 100% repeatable, it might be caused by a broken plugin.
Clean and error check the load order with xEdit before generating LOD as explained above.
If the assertion happens while the xEdit Background Loader loads all plugins, the plugin mentioned in the line above the error has most likely a problem that needs to be fixed. Check that you have the correct version of the plugin for the load order. Redownload and reinstall the mod/plugin.
If the assertion failure is not 100% repeatable or no error can be found in plugins, it could be a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Can not create path
The OS, UAC, antivir or some other 3rd party crapware is blocking write access of the mentioned path. Add an exception to whatever it is that is blocking access.
It is also possible another process or program is interfering with the path creation. In case the closing of other programs does not help, a reboot typically clears such issues.
Try to create the mentioned path with a file manager (for example Windows Explorer) to test if it is possible or so that the tool does not have to create it.
Make sure the (virtual and physical) paths of folders or files are not exceeding the max length limitation.
Duplicates not allowed
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Error reading grass [worldspace] [x,y]
There is a problem reading a grass cache *.CGID/*.GID file. It is probably corrupted and should be regenerated. It could also be in the vanilla Skyrim LE format (Skyrim SE vanilla BSA ship with the Skyrim LE format, hence the vanilla grass cache files do not work).
Find the file in the ..\Data\Grass\ folder and delete it.
The filename is of the form [worldspace]X[x]Y[y].CGID with leading zeros to pad up to 3 digits.
Start the game, open console with ~ and type cow [worldspace] [x] [y] to load into the worldspace and cell so that No Grass In Objects generates the *.CGID file on-demand.
Start DynDOLOD to generate LOD, hopefully without errors this time.
Error while loading images from memory
Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Integer overflow
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Invalid argument
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Item not found
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
List index out of bounds
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Load order FileID * can not be mapped to file FileID for file *
Always use the latest version of DynDOLOD/TexGen as explained above.
This can be caused by errors in plugin. Finalize the load order and clean and error check the load order with xEdit as explained above.
This can be also a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
OpenGL
Applies to any OpenGL or Framebuffer error. The OpenGL messages are typically localized. If they are memory related also check FAQ answers for High memory usage.
Always use the latest version of DynDOLOD/TexGen as explained above.
If this happens while using optional or beta drivers, try installing the latest recommended or official driver instead. Do a clean install. Install the driver only via custom installation options. Do not install crapware shipping with drivers or terminate it before running the tools. Have a look at Radeon Software Slimmer or NVCleanstall.
This can be also a bug with the tools encountering unexpected situations. Add GLDebug=1 under [TexGen|DynDOLOD] in ..\DynDOLOD\Edit Scripts\DynDOLOD\[TexGen|DynDOLOD]_[GAME MODE].INI and make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Ignore outdated suggestions to use older driver versions. If there are still problems after making a clean latest driver only install and removing/terminating crapware, make a proper post on the official DynDOLOD support forum.
Plugin load order too high to copy record into
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Range check error
Always use the latest version of DynDOLOD/TexGen as explained above.
This is a bug with the tools encountering unexpected situations. Make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
Stream read error
This typically related to a problem reading data from an BSA/BA2 archive.
Check the log messages for additional hints which assets is being read. It might give a hint about the archive filename. Try downloading and installing the archive again.
For further help make a report with the log, debug log and bugreport.txt as explained on the official DynDOLOD support forum.
The system cannot find the path specified
The OS, UAC, antivir or some other 3rd party crapware is blocking write access to the mentioned destination path. Add an exception to whatever it is that is blocking access.
It is also possible another process or program is accessing the same folder or file and this is preventing write access. In case the closing of other programs does not help, a reboot typically clears such issues.
Remove old files from the destination/output path, which might prevent creating the new files because they are blocked by other programs.
Make sure the (virtual and physical) paths of folders or files are not exceeding the max length limitation.
Unknown grass data file format
There is a problem reading a grass cache *.CGID/*.GID file. It is most likely in the vanilla Skyrim LE format (Skyrim SE vanilla BSA ship with the Skyrim LE format, hence the vanilla grass cache files do not work).
Find the file in the ..\Data\Grass\ folder and delete it, or in case it is a vanilla *.GID file make sure it is being overwritten with a valid file.
The filename is of the form [worldspace]X[x]Y[y].CGID with leading zeros to pad up to 3 digits.
The mod Grass Cache Fixes comes with a BSA that overwrites the vanilla grass *.GID files which are typically not generated by grass cache generation, since they are in areas that have been removed from Skyrim.esm.