Some DesignBuilder users have reported problems with dsb files becoming corrupted. You may see a message like:

"Error loading file
Filename
This could be caused by trying to read a file created in a more recent version of the software or because the file is corrupt. If you think the file is corrupt you should be able to find incremental backups in the DesignBuilder Data\Backup folder."


There are various possible reasons for this:

• Old DesignBuilder V1, V2 or V3 files need to be loaded first into DesignBuilder v4.2.0.054 and re-saved to rebuild the geometry that can be read in newer DesignBuilder versions. Note that if you are downgrading then you will need to manually delete the library Data folder before starting a new session to access the Detailed HVAC layout screen. The library Data folder will also need to be deleted when installing the newer version to avoid issues with the license service. Instructions to delete the library folder are available here: Remove DesignBuilder library Data folder
• Some special characters are not recognized by our file reader and the corrupted model message may be displayed. Remove and replace these characters from the filename. One example is the left or right single quote character.
• Large models may fail to load due to memory allocation on machines running with a integrated graphics card. To fix this you will need to enable the high spec GPU following the steps described on the article How to check if the computer has a dedicated graphics card ?.
• Dropbox (or similar cloud file sharing system) folders which can lock files for syncing for storage on cloud servers. If you try to work on Dropbox or OneDrive folders your data will eventually become corrupted as DesignBuilder tries and fails to save to a locked file.
• Removable data sticks.
• Opening or saving the dsb file over a network. This operation is not supported by DesignBuilder and corruption problems are far more likely due to possible network errors so you should always load and save to the local disk drive.
• Error in file compression. This can be checked for by opening the dsb file in WinZip, WinRAR or other compression/decompression software. If it opens OK then this is not the cause. Problems with compression may be caused by conflicts with other software installed on the system. If this is the cause then you can work with the skh (uncompressed) format.
• Bugs in some versions of the software can cause problems opening dsb files. It may be worth trying a later version of the software to see if it can read a corrupt file.

If you made a recent Windows restore point or backup then you may be able to retrieve a previous version of the model by right-clicking on the file and select "Restore previous versions".

Cloud sharing systems normally keep a record of files changes and you may be able to find a working version of the model.

However, if the model was produced on a previous DesignBuilder version then in some cases it may be possible to re-open the file on the original version (or on the main release that was available at that time) and re-save it without results. This may fix the loading issue.

If, having followed the above advise, you are still unable to open a file you could try sending it to DesignBuilder Support Desk to see if developers are able to recover it.

See also: http://www.designbuilder.co.uk/helpv6.0/#DesignBuilderModelFiles.htm

Updated 25.Feb.2021