Due to a problem in the ModelSim*-Intel® FPGA Edition 2020.1 and Questa*-Intel® FPGA Edition 2020.2 or earlier, you will get a pop-up error message stating that the "image file format bmp is unknown" when you try to export the wave image in bmp format. This error occurs on Windows* 10 operating system only.
To work around this problem in the ModelSim*-Intel® FPGA Edition 2020.1 and Questa*-Intel® FPGA Edition 2020.2 or earlier, run the following command in the transcript window before exporting the wave image.
package require Img
This problem is fixed starting with the Questa*-Intel® FPGA Edition 2022.1.