Version 2.1.0 installed on Win7 all m$ fixes applied.

1. Drag a file to the file list.

2. Double click the file. A window opens where trim times can be entered:


3. Clicking any of the three buttons ("OK", "Get time from video file", or "Cancel") does nothing.

4. Clicking the close button on MC-TVConverter title bar does nothing.

(While the message section is closed in the above picture, I've done this with the message section open and nothing has appeared there.)

PS: Note the message clipping referred to in a previous topic.

That's strange...
As with your font-size problem, I think this is a local problem. Did you install mctvc to your computer or do you use it portable?
If you have installed it locally please try the following:

1) Copy the mctvc folder to your desktop.
2) Within the root Folder of mctvc on your desktop create an empty textfile and name it "mctvc.portable" (this makes mctvc portable and all settings are stored in "data" folder instead of your profile folder).
3) Start "MC-TVConverter.exe" within this folder and see if the problem persists.

Please also try this on another PC if you are able to. I really think there are some local settings that interfere with mctvc...

Let's keep the font size discussion over at http://mctvconverter.userboard.org/tvconverter-english-discussion-f7/fonts-too-big-win7-tvc-t43.html, and concentrate on the start/stop time trimming problem here.

I notice that the "Set Start Time..." box leads off with "File: Ask This Old House_2014_11_15_14_00_00.wtv" then
"Duration: ---".

Perhaps what's happening here is that the file is being accessed to find out it's length (33 minute in reality), and things are still waiting for the total file size/time to be determined. Then, lacking the total time, edits like "selection too long" can't be done, and mouse clicks on the OK/Cancel boxes aren't being processed because the edit can't be done because the total length isn't known...

I though about this a bit, and tried to get the duration time (instead of dashes) displayed in the window.

1) Waiting it out for several minutes. No luck -- the buttons were still dead.

2) Clicking "Get time from Video File" to get the duration set. Again, including a 10 minute wait, no luck.

The file is about 1.5G long, and was recorded by Win7 MCE. I'd think the play time info in the meta data would be quickly available. But if the whole file actually has to be read, it shouldn't take more than 2 minutes, let alone 10 minutes. Or at least Explorer can copy it in under 1 minute.

I also converted the .wtv file to - DVRMS.dvr-ms (using the MCE built in right click option in Windows Explorer) and the DVRMS file behaved the same as the .wtv file.

What sort of traces/information can I collect for you, pray tell?

Did you try the portable version like I explained above? Did it work?
Did you try this with the same file on another PC?
Do you get this error only on this special file?

I get the time info via ffmpeg. You can check if this fails by right clicking the file in mctvc and select "Streaminfo: FFmpeg". If this fails there may be something wrong with your file. You can try to convert it to ts first (which leaves the original quality intact - check if you have java installed for this!) and then cut the ts file. If all of this fails the only thing you can try is to check "use alternate method to convert files" in settings (AV-Stream) to convert your file to ts and then go on.
If this also fails, your file may be corrupt and I can't do anything about it. (I just call the commandlines for the tools and don't develop them by myself... )