Commit text Links are reset when opening SourceTree

SourceTree version : 3.3.4.3796
When I configure a Commit text Link and close SourceTree I can see the correct configuration in \.git\sourcetreeconfig.json.
If I reopen SourceTree I see that the configured Commit text Link has been deleted.
(just after reopening of SourceTree the file \.git\sourcetreeconfig.json is already overwritten with the deleted configuration)

remark: because the field 'Affects Version/s' is required but my version is not available I added an existing but wrong version in this field. My version : 3.3.4.3796