# Issue with FlightPlot

**URL:** <https://discuss.px4.io/t/issue-with-flightplot/3919>\
**Category:** Uncategorized\
**Created:** [July 18, 2017, 8:23am UTC](https://discuss.px4.io/t/issue-with-flightplot/3919 "2017-07-18T08:23:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![madavraman](https://discuss.px4.io/letter_avatar_proxy/v4/letter/m/94ad74/32.png) [@madavraman](https://discuss.px4.io/u/madavraman)\
**Post date:** [July 18, 2017, 8:23am UTC](https://discuss.px4.io/t/issue-with-flightplot/3919/1 "2017-07-18T08:23:32Z")

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Hi,

I’m able to analyse the attached log with [logs.px4.io](http://logs.px4.io), but if I try to open it with latest flightplot either from the master branch or using release binary I get the error java.nio.InvalidMarkException.

I have attached my log file here. Can anyone confirm if I have to change the format of the file from px4log before opening it with FlightPlot?

Also if I open the sample log from [https://pixhawk.org/dev/flightplot](https://pixhawk.org/dev/flightplot), FlightPlot is able to analyse and if I download the .ulg file from the [logs.px4.io](http://logs.px4.io) for the uploaded log then also FlightPlot is able to open the logs.

> **[log\_1\_UnknownDate.px4log](https://www.dropbox.com/s/b1epayqreodkirn/log_1_UnknownDate.px4log?dl=0)**
>
> Shared with Dropbox

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**Author:** ![bkueng](https://discuss.px4.io/letter_avatar_proxy/v4/letter/b/2bfe46/32.png) [@bkueng](https://discuss.px4.io/u/bkueng)\
**Post date:** [July 18, 2017, 4:15pm UTC](https://discuss.px4.io/t/issue-with-flightplot/3919/2 "2017-07-18T16:15:49Z")

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Hi

Yes you just need to change the file extension. The downloaded file from [logs.px4.io](http://logs.px4.io) is exactly the same as the one you upload.

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<div class="post-metadata">

**Author:** ![madavraman](https://discuss.px4.io/letter_avatar_proxy/v4/letter/m/94ad74/32.png) [@madavraman](https://discuss.px4.io/u/madavraman)\
**Post date:** [July 19, 2017, 12:58pm UTC](https://discuss.px4.io/t/issue-with-flightplot/3919/3 "2017-07-19T12:58:24Z")

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Thanks a lot @bkueng, just changing the extension did the magic. Changing the file extension to .ulg worked, lolz 😄