SharpCap Forums

Hello,
I have been using SharpCap for several years with great satisfaction. I recently changed various elements in my setup and a recurring bug has appeared.
I don't know what is causing the bug because a lot has changed. And it appears randomly. I do solar astronomy.
First, I changed my PC. The new PC is an Intel I9 mini PC with 32GB of RAM and Win11. I have been using a 2TB SanDisk Pro SSD for several years. It is connected to a USB 3.2 port. What is new is that I am using two ASI432M cameras that simultaneously record two different fields. They are both on separate USB 3.2 ports. They therefore have write access to the SSD.
At the same time, I am using Sylvain Weiler's clever software called GOESSS SunGun (http://sweiller.free.fr/Softwares/GOESS ... SunGun.htm). This software deletes the SER files recorded during the session when solar activity remains below a certain threshold. It also has write access to the SSD. It is possible that one of these devices or software programs is interfering with SharpCap's reading or writing? In any case, SharpCap crashes randomly with the message “The default capture folder of D: \ was not found or SharpCap cannot write to the folder”... Then it freezes and even the Task Manager cannot close the current SharpCap session. Note that the other session is not stopped and continues to function normally.
I have saved the log files from the latest crashes... I hope they will be useful. I have uploaded them to DropBox: https://www.dropbox.com/scl/fo/fifok4rq ... l7fnp&dl=0
The most recent (15.08.2025 between 10:45 and 11:54) are probably the more pertinent. Ideally, if you could help me identify what is causing SharpCap to crash (SSD access conflicts, need for two separate SSDs for the two cameras, etc.), that would be great.

Thank you for your help
Best regards
Christian

Hi Christian,

that's interesting, since I saw one of your uploaded bug reports a day or so ago, but I couldn't make any sense of what was going on. With the context you have given, it starts to be a bit more understandable, but it's still odd...

SharpCap does a series of checks before starting a new capture to make sure that the main capture folder exists and can be written to - this provides an opportunity to show a useful error message if there is a problem, rather than to crash awkwardly later when trying to create an SER or FITS file or whatever. It helps catch things like misconfiguration (read only folder chosen, or no permission to write to the folder) or the unexpected loss of an external USB drive being used as a capture folder.

What's probably most relevant here is that two of the checks are

* Asking windows if the main capture folder exists
* Checking that a text file can be written to the folder (it's the easiest and best way to check for the correct permission to write to the folder).

In the uploaded bug report and the logs I have looked at so far, the problem is caused by the first check *hanging* somewhere inside Windows code rather than simply succeeding or failing. SharpCap is completely stuck waiting for the frozen check for the existence of the directory to complete.

I am speculating that somehow the SunGun software is triggering this problem, but I can't see an obvious reason why or how. It's not something that I can really fix in SharpCap, since I'm basically asking Windows a simple question expecting a yes/no answer and getting a 'I'm never going to give you an answer' response.

I think a good thing to try would be to set your capture folder to a folder on the D:\ drive - like d:\captures - rather than to just d:\. I can't be sure that this will help, but there are differences in how Windows handles sub folders on drives compared to the top level folder, so it's just possible that the issue may not show up if you work entirely in a subfolder.

cheers,

Robin

Dear Robin,

Thank you for your answer. I will try it asap and will give you a follow up.

Have a nice end of week-end
Best regards
Christian