Recently I faced an issue where the Data Base synchronization for D365 F&O was throwing the error where as all the Build was successful even after move all the code from another environment.
Here I would to mention one important thing which I was completely ignoring was "We were using ISV solution from another party ".
Error -
Although it was a long error log but from it you could find the below main part which will try to expose error detail.
An attempt was made to load an assembly from a network location which would have caused the assembly to be sandboxed in previous versions of the .NET Framework. This release of the .NET Framework does not enable CAS policy by default, so this load may be dangerous. If this load is not intended to sandbox the assembly, please enable the loadFromRemoteSources switch
As I mentioned we were using ISV solution so it was the only reason for this Sync Failed. I had to follow the below process to make a successful Sync.
1- Go to the Local directory location "K:\AosService\PackagesLocalDirectory"
2- Got to the package folder in directory ""K:\AosService\PackagesLocalDirectory\###Package (ISV Package)"
3- Find the DLL file here .
4- Right click and open "Properties"
5- here you will find one Unlock check box. we need to check this box and run the Sync for DB again.