# Failed to load external drawtext plugin 'libptbdrawtext\_ftgl64.dll'

**URL:** <https://psychtoolbox.discourse.group/t/failed-to-load-external-drawtext-plugin-39-libptbdrawtext-ftgl64-dll-39/263>\
**Category:** Uncategorized\
**Created:** [July 13, 2017, 12:01pm UTC](https://psychtoolbox.discourse.group/t/failed-to-load-external-drawtext-plugin-39-libptbdrawtext-ftgl64-dll-39/263 "2017-07-13T12:01:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [July 13, 2017, 12:01pm UTC](https://psychtoolbox.discourse.group/t/failed-to-load-external-drawtext-plugin-39-libptbdrawtext-ftgl64-dll-39/263/1 "2017-07-13T12:01:05Z")

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Hi,

I have compiled an application under matlab that is using the psychtoolbox.

See below the error message I get.

I am running the exe in a laptop (windows 10) that has just the MCR (no matlab).

Any suggestion how to solve it ?

Thanks,

Tal.

PTB-DEBUG: DrawText: Failed to load external drawtext plugin [Unknown error].

PTB-INFO: DrawText: Failed to load external drawtext plugin 'libptbdrawtext\_ftgl64.dll'. Reverting to legacy GDI text renderer. 'help DrawTextPlugin' for troubleshooting.

PTB-ERROR: Screen('Flip'); beamposition timestamping computed an \*impossible stimulus onset value\* of 87880.300899 secs, which would indicate that

PTB-ERROR: stimulus onset happened \*before\* it was actually requested! (Earliest theoretically possible 87880.307009 secs).

PTB-ERROR: Some more diagnostic values (only for experts): rawTimestamp = 87880.311407, scanline = 680

PTB-ERROR: Some more diagnostic values (only for experts): line\_pre\_swaprequest = 385, line\_post\_swaprequest = 395, time\_post\_swaprequest = 87880.307163

PTB-ERROR: Some more diagnostic values (only for experts): preflip\_vblcount = 25, preflip\_vbltimestamp = 87880.317547

PTB-ERROR: Some more diagnostic values (only for experts): postflip\_vblcount = 0, postflip\_vbltimestamp = -1.000000, vbltimestampquery\_retrycount = 0

PTB-ERROR: This error can be due to either of the following causes (No way to discriminate):

PTB-ERROR: Either something is broken in your systems beamposition timestamping. I've disabled high precision

PTB-ERROR: timestamping for now. Returned timestamps will be less robust and accurate, but if that was the culprit it should be fixed.

PTB-ERROR: An equally likely cause would be that Synchronization of stimulus onset (buffer swap) to the

PTB-ERROR: vertical blank interval VBL is not working properly.

PTB-ERROR: Please run the script PerceptualVBLSyncTest to check this. With non-working sync to VBL, all stimulus timing

PTB-ERROR: becomes quite futile. Also read 'help SyncTrouble' !

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**Author:** ![gat\_tal](https://avatars.discourse-cdn.com/v4/letter/g/ebca7d/32.png) [@gat\_tal](https://psychtoolbox.discourse.group/u/gat_tal)\
**Post date:** [October 4, 2017, 10:03am UTC](https://psychtoolbox.discourse.group/t/failed-to-load-external-drawtext-plugin-39-libptbdrawtext-ftgl64-dll-39/263/2 "2017-10-04T10:03:50Z")

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I install gstreamer according to the guideline, put it in the place it was written, seems to work fine.