When I try to open the file in Solidworks, I get this warning. Also it have never recorded when the "auto-recovery" option is turned on unfortunately... This file very important to me, please help.
"An error was encountered while trying to open your file. Contact Technical Support for a possible solution"
My guess would be, you are using files from different versions or sometimes I have experience this error even with same version but different licences. There are a couple of ways to work around.
You can go to https://www.3dcontentcentral.de/ and upload your content and change the version or format and download it for later modificaiton.
Or get the STEP/IGES file from the person where you got the file from
Or if it your own file and have problems with it, contact the Technical Support. They are very helpful in such cases.
Are you trying to access the file from a network location? If so I can think of 3 things to try:
First, try opening the assembly in SolidWorks eDrawings, if that loads it fine it should indicate an issue with your SolidWorks program or if it can't load it then it would indicate a problem with the assembly file itself.
Second, try copying the file to your local drive and opening it from there.
Third, if you can, try having another user's computer open the file.