The Translation Provider ‘blah blah blah’ could not be opened and has been disabled

Question

Hi, 
 I am working on developing a plugin to offer our Machine Translation services to SDL Trados Studio users. To build plugin, I started with SDL Translation Provider project template. 
 I implemented few functions of classes implanting ITranslationProviderWinFormsUI, ITranslationProvider Interfaces. Somehow, with the help of DeepL and ETS plugins developed by SDL Community, I successfully deployed my plugin and shown a GUI to input Api Key. But after that, SDL Studio gives following error: 
 &ldquo;The Translation Provider &lsquo;blah blah blah&rsquo; could not be opened and has been disabled.&rdquo; 
 Afterwards, plugin gets added but remains disabled. 
 The DeepL plugin is also giving same error but it remains enabled after adding till the time of selecting files for translation. 
 I must say that there is very little help on how to start developing a plugin. There should be step by step guide including detailed explanation of events especially when an event will be triggered. 
 
 Please help me to resolve this issue. 
 Thanks

Rob Cole · Accepted Answer

I found the root cause of this problem. 
 I implemented "Browse" function of "ITranslationProviderWinFormsUI" interface. This function returned an array of ITranslationProvider objects. In this function, I stored credentials in the credential store. After that, "CreateTranslationProvider" function of "ITranslationProviderFactory" triggered. I tried to get credentials from credential store in this function but it is returning null. I was throwing exception if credential is null. I just commented this exception and plugin loaded successfully.

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The Translation Provider ‘blah blah blah’ could not be opened and has been disabled