I have just installed Altaro Physical Server Backup and it errors when trying to take a backup. The error code is:

Type 'Altaro.Store.Services.Server.Deduplication.RealmMapping' in assembly 'Altaro.Store.Services.Server, Version=2.0.3.0, Culture=neutral, PublicKeyToken=null' has method 'OnSerializingMethod' with an incorrect signature for the serialization attribute that it is decorated with.

I was in the process of migrating all the data to a new virtual server but one of the disks in the raid is now showing as a predicted failure. 

Any ideas

after install the new version .net 4.7.2 is working 

I have the same problem with my Windows Server 2012 R2. What version  .NET need to be installed. We have on that server .Net 4.7 

It turned out to be updates for net 4.7.

I'm getting the exact same error, 

Type 'Altaro.Store.Services.Server.Deduplication.RealmMapping' in assembly 'Altaro.Store.Services.Server, Version=2.0.3.0, Culture=neutral, PublicKeyToken=null' has method 'OnSerializingMethod' with an incorrect signature for the serialization attribute that it is decorated with.

here is the log...