Applies To:
  • CitectSCADA 3.xx, 4.xx, 5.xx

An 'Invalid Object Thumb' error box comes up when I try to open a symbol for editing via 'File Open' form, but it only happens on some symbols.  I can still edit the symbol if I use the 'Edit' button located on the 'Paste Symbol' tool.  

The error is caused by Citect being unable to create/open a preview image for the symbol, if you un check the 'Preview enable' option on the 'File Open' form it will stop the error box coming up.  The problem seems to be linked to the format & application in which the symbol was originally created, the symbols I experienced the problem with were created in 3D studio Max & saved as bitmaps, then opened in Paint Shop Pro had the number of colours decreased to 256 & then re-saved.