Regarding the issues you have reported:
1) The first issue, related to many-to-many relationship.
We have reproduced it, the problem is that the Auto-Synс property is set to 'OnInsert' for the 'OrderId' and 'CompanyId' properties (which are the foreign keys) in the 'CompanyOrders' entity class. In this situation there is no need in synchronization, as you insert the known values into the third table. Thus, please set the Auto-Synс to 'Never' for these two fields and save the changes.
As for the error when working with SQL Server, we will investigate it.
2) The second issue (Devart Sample 1 from: http://rghost.ru/44425941
) - we don't get any exceptions with this sample. Please specify the following:
- what exactly errors you are getting with it;
- the versions of MySQL and SQL Server you are working with;
- the SQL script for creating database tables, that correspond to Order and Company entity classes (we have created these tables from your model, thus there may be some differences in them);
- the exact steps to reproduce (e.g., what events should be tested).
Looking forward to your reply.