1800 File Open Error in Delphi / C++Builder IDE

If you have a table ACTIVE and opened in EXCLUSIVE mode during design-time, running the application from within the IDE will result in an 1800 File Open Error. This is because the IDE has the file opened EXCLUSIVE already, and now your application is also attempting to open the same file in EXCLUSIVE mode. Running the application from outside of the IDE will not result in the 1800 error.

To solve this problem during design-time, either set the TApolloTable.Exclusive property to False (at least during development), or if you must have the file opened EXCLUSIVE, you'll need to set TApolloTable's Active property to False during design-time and set it to True in your application code (i.e., in your main form's OnActivate event).