Remove all elements of that MASlopeMultiV3.10.

For removing the DLL: First try to remove it via File -> Edit -> Remove NinjaScript Assembly. If that does not work you need to remove it manually. I was not able to try this method do to the original error message.

To remove it manually: Go to folder My Documents -> NinjaTrader 7 -> bin -> custom. Delete the files labelled MaSlopeMulti *.*. If you remove the DLLs manually, you also need to remove the references manually. I successfully removed the DLL from this folder and proceeded to the next step.

To remove references: Edit any indicator and right-click into the editor with your mouse. Select "References" and remove reference to the DLL. This is where I may have made my mistake, there was still a reference to the MASlopeMulti.dll, however after deleting the file I restarted and did not have any luck in the original error message problem. Therefore, I came back to the reference section and also removed the remaining DLL files (probably wasn't the best idea on my part), and am now in a further problem than before I believe?!? Any thoughts?

After this exercise shut down NinjaTrader and restart again.

Thank you @Fat Tails for your help this morning in resolving my NT error problems.
Everything is back up and running perfectly!

NJ was running ok until I put a anaholtema.cs into the custom/indicator folder

after that i could not import scripts through utility and got the darn message,..... custom indicator error,,,,,,
i deleted it and the indicator was not even used because it was not visible in the indicator list.

I was experimenting edit scripts and i tried to copy the whole chunk into another indicator and there was error when I compiled. I tried to compile another indicator that is working find and also have error message.

seems something just mess up.

If you copy and paste around for sure you will run into problems, if you do not understand how to do it. The error messages are generated because you have

- either files with coding errors
- or files that reference missing files

None of these problems can be attributed to the anaHoltEMA, because

- it does not have coding errors
- it does not reference any external files

If you want to get rid of your mess, please post a screenshot of the error messages after compiling. Alternatively you can also have a look at you log and trace files and inform us about the error messages that you find there.

This is my second time experiencing the problem.
Last week. I copied files into the indicator folder and had the same problem.
I deleted them and voila, it worked.

However, I wanted to attempt again today, if a particular file is a problem. Okay, it may not be the right way
I could not even run the anaHoltema because it did not appear on the indicator list in NJ, but it is in the folder and visible.

I then attempt to import through utilities and the error message about custom indicator error....
I have read through the log file, no idea what is the issue.
can I pm you the log file?

Edit any of your indicators and compile. Post a screenshot of the error messages shown by the editor.

ONE corrupted indicator seems to affect the rest. I am surprised how other files could be affected. they had to be deleted and then it would work.