DIXF | Error while importing product data from staging to target

When importing product data with the data import export framework into dynamics ax I faced the following error:

SysDictTable Objekt ist nicht initialisiert. 

Stack-Trace 
(C)\Classes\DMFEntityWriter\write - line 244 
(S)\Classes\DMFEntityWriter\runOnServerWriter - line 14 
(C)\Classes\DMFEntityWriter\run - line 98 
(C)\Classes\DMFEntityWriter\main - line 24 
(C)\Classes\xMenuFunction\run 
(C)\Classes\MenuFunction\run - line 85 
(C)\Forms\DMFWriteData\Designs\DesignList\DMFEntityWriterBatch\Methods\Clicked - line 23

Checking the code I found out that this is where the table structure is taken and the targettbales are added to a query. There I noticed that one table from the structure could not be found. But why that?

First thing I tried was opening the target mapping > refresh and regenerate the mapping, without a result. After a bit more debugging I found out that the Table that created this error was the RetailInventTable which was not available because the config keys for retail was disabled.
So I checked the entity structure and tried to remove it. But we are not allowed to delete here.

To fix this I had to go into the development workspace. Navigate to Queries > DMFProductTargeEntity > DataSources > InventTable > DataSources and delete RetailInventTable here.
After that navigate back to the target mapping > refresh and regenerate the mapping. Have a look at the entity structure. The Table that created the problem is no longer in there.

After that change the import to target is working fine :)