Exposure times and corrupted anycubic files

[Prafs11]

Hello fellow printers,
I am currently doing a very unorthodox use of an Anycubic M4 Ultra, as I am a researcher and in between other things I work on developing new materials to print as well. I love UVtools as it is superhandy and it allowed me to unpack anycubic printing files and modify some things, however I run into an issue. I modified the exposure times of the base layers and the normal layers from UV tools, however when I export the file to make a .pm4u printing file I am unable to open it from Photon Workshop and the printer refuses to print it, an gives an error message on the file being corrupted. If I do basically the same changes in exposure time from Photon Workshop by adding a new material and changing exposure options the file works. Any idea of why? Ideally I would dream of being able to set different exposure times for each layer if I wished so, but I feel like Anycubic really prevents the user from changing much in the printing file.

[sn4k3]

If you only editing global properties for bottom and normal layers this should happen.
Can you provide the original and modified file?

Ideally I would dream of being able to set different exposure times for each layer if I wished so, but I feel like Anycubic really prevents the user from changing much in the printing file.

You need a proven printer to do such.

[Prafs11]

Thank you for the answer! Unfortunately I have deleted the printing files that were not working. I had modified the exposure times from UV tools under Tools>Edit print parameters and simply setting a number of base layers with an exposure and the rest of the layers with another one, with no transition layers. What I found curious is that I used the same identical exposure time and layers from Photon Workshop and it worked. Anyway, as mentioned in my original message I am aware that I was trying to use the printer in a very unorthdox way and I know that if I want to go in the direction of varying the exposure time along layers I should go for a different printer. Thank you so much!