Hi. I believe you need to modify your 64b R/T application to migrate away from the use of "set next document parent", which has been deprecated. If you refer to the Sample Applications delivered with v16 MapBasic, you can find examples of re-parenting windows using the IMapInfoPro.CreateUnattachedWindow() api. Specifically, refer to
- SAMPLES/RIBBONINTERFACE/DotNet/UnattachedWindow
- SAMPLES/RIBBONINTERFACE/DotNet/UnattachedWindowMB
Once you've had a look at these, or if you already have, and you still have problems, please post again with more details.
Thanks.