Java exception when trying to import image sequence

Posted by asteroidguy on Jun 08, 2022; 10:50pm
URL: http://astroimagej.170.s1.nabble.com/Java-exception-when-trying-to-import-image-sequence-tp1944.html

Running AIJ 5.0.3.02 for a while, the Import -> Image Sequence function suddenly stopped working. It throws the following exception:

AIJ 5.0.3.02; ImageJ 1.53k; Java 17.0.1 [64-bit]; Windows 10 10.0; 11MB of 3000MB (<1%)
 
java.lang.NullPointerException
        at java.base/java.io.File.<init>(Unknown Source)
        at ij.plugin.FolderOpener.getFileCount(FolderOpener.java:799)
        at ij.plugin.FolderOpener.showDialog(FolderOpener.java:579)
        at ij.plugin.FolderOpener.run(FolderOpener.java:151)
        at ij.IJ.runPlugIn(IJ.java:208)
        at ij.Executer.runCommand(Executer.java:151)
        at ij.Executer.run(Executer.java:69)
        at java.base/java.lang.Thread.run(Unknown Source)

I was going through numerous directories in a AIJ instance that was already running for a long time when that error suddenly happened. I am unable to clear the error - neither restarting AIJ nor starting with a fresh setup of AIJ5 do help. I am afraid something must have upset the file import dialog window. How can I recover from this error?

EDIT: Edit -> Options -> Reset... provided the remedy, but not sure how I managed to throw it off in the first place...