Troubleshoot

There are numbers of possibility that can cause this problem,

1. File corrupted – This error is caused by file corruption. It can be due to a feature/entity/relation, etc. There is no way to fix the issue other than sending it to the SOLIDWORKS development team. SOLIDWORKS has some kind of tools using which they can fix the file.
2. Assembly component saved in higher version – The message will appear when one of the part files was saved in the higher version then you open the assembly in the lower version.
3. Large assembly – When working on a large assembly file with an external reference use in it, it could lead to this error.
4. The most likely culprit is SOLIDWORKS itself – That’s the reason SOLIDWORKS came out with a number of the service packs, which is to fix those issues.

There a few solutions to this issue.

1^st Method

1. Create a new assembly and then add that component into it.
2. Save as a new assembly.

2^nd Method

1. Open SOLIDWORKS and then drag and drop the file into the SOLIDWORKS graphic area.

3^rd Method

1. Go to File -> Open
2. Choose the assembly file then click at the ‘Configuration’ and choose ‘<Advanced>’
3. Click Open

4. The Configure Document windows will pop up, choose the 3^rd option which is ‘New configuration showing assembly structure only’.
5. Add a name for this new configuration.

6. The Assembly will open and all parts and sub-assemblies will be Suppressed.

7. Select all components and choose unsuppressed to recover back the file.